Leave the installation of solar panels in Ashigarakami District, Kanagawa Prefecture (Nakai Town, Oi Town, Matsuda Town, Yamakita Town, Kaisei Town) to Kakeru Koumuten Co., Ltd.!
For
Solar Panel and Storage Battery Installation in
Ashigarakami District, Kanagawa Prefecture, trust
Kakeru Koumuten!
Kakeru Koumuten is a specialized exterior renovation company headquartered in Aoba Ward, Yokohama City.
As a company strong in roofing work, we are entrusted with solar panel and storage battery installation considering roofing and waterproofing!
“How to Choose a Solar Panel Contractor in Ashigarakami District”
“Costs for Solar Panel and Storage Battery Installation”
“Subsidies Available for Solar System Installation in Ashigarakami District”
We will also explain the above three points!
Installing solar panels carries risks such as “the occurrence of leaks” and other troubles.
To ensure a satisfactory solar panel installation, we recommend obtaining three or so estimates!
Table of Contents (Tap to Expand)
- Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Ashigarakami District, Kanagawa Prefecture
- Roof Inspection Before Installing Solar Panels
- Subsidies and Grants That May Be Available in Ashigarakami District
- Price List for Solar Panel and Storage Battery Installation
- Breakdown of Installation Capacity, Equipment, and Construction Costs
- Self-Estimate and Profit Simulation for Solar Power Generation
- Customer Testimonials
- Case Studies of Solar Panel Installations
- How to Choose a Solar Panel Installation Contractor in Ashigarakami District, Kanagawa Prefecture
- Benefits of Introducing Solar Equipment
- Points to Consider When Introducing Solar Power Generation
- How to Choose Solar Panels
- Frequently Asked Questions About Solar and Storage Battery Installation in Ashigarakami District
- If You Are Looking for a Solar Panel Installation Contractor in Ashigarakami District, Contact Kakeru Koumuten
- Characteristics of Ashigarakami District, Kanagawa Prefecture, and Points for Solar Construction
- Service Area in Ashigarakami District, Kanagawa Prefecture
Reasons Why Kakeru Koumuten is Chosen for Solar Panel Installation in Ashigarakami District, Kanagawa Prefecture
The reasons our company is entrusted with solar panel installation by customers in Ashigarakami District, Kanagawa Prefecture include
one reason being that Kakeru Koumuten has a base in Kanagawa Prefecture,
and our unique strengths in solar panel installation that cannot be imitated by other companies, which have received high praise from many customers.
so we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome estimates from any number of companies!
1. We Can Also Handle Exterior Renovations Other Than Solar Panel Installation!
Issues such as leaks that occur during solar panel installation may be caused by insufficient checks on the roof and waterproofing at the installation site.
Even if you are knowledgeable about solar panels, there are cases where the roof and waterproofing at the installation site are outside your expertise, so caution is necessary.
It is reassuring to have expertise in roofing to avoid maintenance and troubles after installation!
Kakeru Koumuten Co., Ltd. is strong in roofing work and can also detach and attach solar panels in-house, allowing for quick responses to maintenance and urgent troubles after solar panel installation!
2.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has organized the following warehouses and material storage areas to provide low-cost, high-quality solar work and exterior renovations.
We have established five bases centered around Yokohama City, Kanagawa Prefecture for material storage and showrooms.
In-house Scaffolding Materials
To ensure safety during work on the roof, we own the scaffolding materials necessary for temporary scaffolding based on construction conditions and can assemble scaffolding in-house.
By performing scaffolding work with our own scaffolding team instead of outsourcing, we can also cut costs for scaffolding work.
We own scaffolding materials for approximately 50 detached houses!
Even in the Ashigarakami District, where residential areas spread from the Ashigara Plain to hilly and mountainous areas, our in-house scaffolding team plans scaffolding according to the local conditions.
Storage of Materials in Our Large Warehouse
We store roofing materials and paints, and we can also store removed solar panels.
By ordering a large quantity of materials at once, you canpurchase materials at a lower cost!
Additionally, we always have a stock of roofing materials, so we canrespond quickly in emergencies!
In-house sorting and transportation of waste materials
The installation of solar panels often involves roofing work, generating various waste materials such as paint, wood, and metal.
By sorting and recycling waste materials, we can significantly cut waste disposal costs.
Exterior renovation dedicated showroom
In the showroom, not only can you have meetings, but you can also
check the actual foundation brackets for solar panels and see how they are attached to the roofing materials!
We can also provide simulations of the revenue and installation costs when introducing solar panels!
Since roofing and exterior wall work often accompany projects, we also have samples of roofing materials and models that explain the structure, allowing us to provide detailed explanations!
3.All work performed by our own team
One of Kakeru Koumuten’s major strengths is complete in-house construction.
By having Kakeru Koumuten handle everything from inquiries to project completion in a consistent manner, we can keep costs down and provide high-quality roof renovations.
Additionally, one representative will assist you from the estimate to the completion of the work.
Since the same person will handle sales and construction management, smooth communication is possible.
We can provide consistent in-house construction from temporary scaffolding setup, exterior wall painting, to roof renovations!
4. Various Permits Obtained & Skilled Workers on Staff
We have obtained construction industry licenses and permits for industrial waste collection and transportation!
We also have nationally certified sheet metal and painting technicians on staff, and we are confident in our construction techniques.
We can also handle large-scale roof work for factories and other buildings!
5. Warranty and Aftercare Maintenance
In addition to the manufacturer’s warranty for solar panel installation work, we also provide our own construction warranty (leakage warranty)!
(The construction warranty for solar panel installation is 10 years. Depending on the condition of the roof before installation, we may not be able to provide a warranty unless a roof renovation is performed. The construction warranty is separate from the manufacturer’s product warranty, and the scope and conditions vary depending on the warranty details.)
Aftercare maintenance is available annually, and we send out notification DM every year.
If you have questions about the warranty, please click on the image above!
6. Flexible and Prompt Response
Our company is equipped to handle various roofing troubles and situations.
Even if you cannot access the roof at high altitudes, we can respond using a drone!
During leak investigations, we can also conduct inspections using a thermal imaging camera.
If the power generation of your solar panels decreases due to dirt or other factors, we can also provide cleaning services for solar panels using specialized brushes.
We will respond according to your wishes.
7. Human Resource Development
To improve skills, we create various roof models and conduct practical training.
Since the construction methods vary depending on the shape and slope of the roof, we regularly conduct technical training to ensure that each staff member can handle various cases.
8. Creation of Easy-to-Understand Materials and Simulations
Kakeru Koumuten provides “estimates”, “layout diagrams”, and “power generation simulations”, as well as “solar construction guidebooks” and “profit and loss simulations” that take into account loan interest rates and electricity costs.
Profit and loss simulations can be created for projected cumulative profits and losses over 20 to 30 years.
Even customers who are not familiar with solar construction will receive materials that clearly summarize important points and disadvantages!
We encourage you to obtain comparative estimates and compare them with other companies’ plans!
Roof Inspection Before Installing Solar Panels
Once solar panels are installed, they will remain on the roof for 20 or 30 years.
Confirming “whether it is okay to install them directly on the current roof” before installation is the key point to prevent leaks and unnecessary expenses!
Kakeru Koumuten, which specializes in roofing work, has summarized the items to check before installation.
| 1. Types of Roofing Materials and Age | The fixing method varies depending on the roofing materials, such as slate, tiles, metal roofs, and flat roofs (roof waterproofing). If the remaining lifespan of the roofing material is short, we may suggest a roof renovation first. |
| 2. Condition of Substrate and Waterproof Sheet | If the sheathing boards or roofing (waterproof sheet) under the roofing material are damaged, it will affect the fastening strength and waterproofing. We will also check for any signs of leaks. |
| 3. Orientation, Slope, and Shadows of the Roof | The orientation and slope of the roof surface, as well as shadows from neighboring houses, trees, and utility poles, will affect the power generation. We will create a layout diagram from the drawings and the site, and you can confirm it with a power generation simulation. |
| 4. Shape of the Roof and Usable Area | The number of panels (installation capacity) that can be placed depends on the shape and size of the roof. Since the number of panels that can be installed varies depending on the size of the panels, we will compare based on the total output of the roof. |
| 5. Fixing Method and Waterproofing Details | We will check whether the method involves drilling holes in the roofing material for fastening or using brackets to secure the roofing material. The fixing method varies by technique, so please confirm the waterproofing treatment method for the fixed parts during the estimate. |
| 6. Weight of the Roof | The roof will become heavier due to the panels. After investigating the existing roof, substrate, and load-bearing capacity, replacing with lighter roofing materials may also be an option if necessary. |
| 7. Installation Location of Equipment and Wiring | We will confirm the installation location of the power conditioner and storage battery, as well as the wiring route to the distribution board. The length of the wiring will also affect the cost. |
Fixing Methods and Checkpoints by Roofing Material
| Roof Material | Main Fixing Method | Pre-Installation Check Points |
|---|---|---|
| Slate Roof | Varies by method (e.g., fixing brackets to the roof material and substrate with screws) | Waterproofing treatment of fixing parts, cracks or deterioration of slate, condition of the substrate. If deterioration is advanced, consider roof overlay or replacement first. |
| Tile Roof | Fixed with brackets and methods suitable for the type of tile (even methods that do not drill holes in the tiles will fix to the substrate) | Type and condition of tiles, substrate, load-bearing capacity. Depending on the investigation results, there may be methods to replace with lightweight roofing materials before installation. |
| Metal Roof (Horizontal and Vertical) | Fixed with catch-type brackets that grip the roof material (depends on the combination of roof material and brackets) | Whether the roof material and brackets are compatible, installation conditions from the roof material manufacturer. If compatible, methods that do not drill holes may be available. |
| Flat Roof / Rooftop | Fixed by installing a frame | Type and deterioration status of the waterproof layer, waterproofing details around the frame. Consider in conjunction with the timing of waterproofing work. |
If you renovate the roof 10 to 20 years after installation, there will be additional costs for removing and reinstalling solar panels. If the roof is deteriorating, renovating to a highly durable roofing material before installation may help reduce costs in the long run.
Kakeru Koumuten is strong in roofing work and can also handle the removal and reinstallation of solar panels in-house, so please consult us according to the condition of your roof!
▶ Click here for roof renovations in Ashigarakami District, Kanagawa Prefecture
PossibleSubsidies and Grants
If you are introducing solar panels or storage batteries in Ashigarakami District (Nakai Town, Oi Town, Matsuda Town, Yamakita Town, Kaisei Town), you may be eligible for programs from “the national government,” “Kanagawa Prefecture,” and “Nakai Town, Oi Town, Matsuda Town, Kaisei Town.”
The following information is based on the official pages of each program as of October 6, 2026. The application status may change depending on the budget and recruitment period, so please check the latest information before contracting or starting work.
Eligibility Conditions and Application Timing for Subsidy Programs
| System | Main Eligibility Conditions | Subsidy Amount | Application Period & Status |
|---|---|---|---|
| Nakaitown “Household Solar Power Generation System, HEMS, and Storage Battery Installation Subsidy” | Individuals installing in their own homes within the town, who have a lighting contract and no tax arrears. Must apply to the Nakai Eco Monitor and be able to cooperate with a one-year report. Application must be made before installation/start of work (if only for storage batteries, they must be installed in connection with the solar power generation system) | Solar: 15,000 yen per kW (maximum 52,000 yen) HEMS: 10,000 yen (fixed amount) Storage Battery: 50,000 yen (fixed amount) |
Applications accepted in order of submission (only in person). May close due to budget constraints. Performance reports are due by March 19, 2027 |
| Oitown “Subsidy for Introduction of Residential Smart Energy Equipment” | Individuals residing (including those planning to) in the town with a lighting contract, and no tax arrears. Must be the owner of the building or have written consent from the owner. Installation must occur after receiving the grant approval notification | Solar: 20,000 yen per kW (maximum 100,000 yen) HEMS: 20,000 yen (fixed amount) Storage Battery: 50,000 yen (fixed amount) |
From April 1, 2026, on a first-come, first-served basis. According to the town’s announcement (as of August 1, 2026), there are plans for 30 solar, 20 HEMS, and 20 storage batteries, with remaining slots being less than 10 for solar and HEMS, and less than 5 for storage batteries |
| Matsudatown “Smart House Development Promotion Project Subsidy System” | Individuals with a lighting contract who will install in their own residence within the fiscal year. Owner’s consent and payment of town taxes are required, and installations via lease or PPA are also eligible. Application is required before starting construction | Solar: 20,000 yen per kW (maximum 100,000 yen) Storage Battery: 50,000 yen (fixed amount) HEMS: 10,000 yen (fixed amount), etc. |
First-come, first-served within the budget of 3,750,000 yen for the fiscal year 2026 (mail applications are not accepted). Performance reports are due within 30 days of installation completion or by March 15, 2027, whichever comes first |
| Kaiseitown “Zero Carbon City Creation Subsidy System” (Subsidy for Smart House Conversion of Existing Homes) | Existing homes in the town that are over one year old are eligible. For solar power generation, conditions include self-consumption of more than 30% of the generated electricity and not using the FIT system. | Solar: Up to 120,000 yen per kW (for priority measures acceleration subsidy, up to 4 kW. Over 4 kW is 70,000 yen/kW), otherwise 50,000 yen/kW (maximum 200,000 yen) Storage batteries, HEMS, and additional installations of three or more systems are also eligible (please check the town’s materials for details) |
Recruitment starts on July 1, 2026. Application deadline is February 15, 2027 (for priority measures acceleration subsidy, March 15). This is a limited-time system until the fiscal year 2026 |
| Yamakitown | The official town website does not confirm any unique subsidy system for solar power generation or storage batteries for residential use. | (There may be applicable programs from Kanagawa Prefecture or the national government) | Please contact Yamakitown for the latest information |
| Kanagawa Prefecture “Reiwa 8 Annual Kanagawa Prefecture Subsidy for Residential Solar Power Generation and Storage Battery Installation Costs” | To install solar power generation and storage batteries together in a residential building or apartment in the prefecture that ensures seismic performance. Applications must be made by the individual, and construction can begin after the grant decision. | Solar: 70,000 JPY/kW Storage Battery: 150,000 JPY/unit |
Phase 1: May 11, 2026 – June 30, 2026 Phase 2: September 7, 2026 – September 30, 2026 (first-come, first-served) Phase 2 has reached its application deadline. Please check the prefecture’s official page for future recruitment. |
| National “DR Home Storage Battery Project” (Reiwa 7 Annual Supplement) | New installation of home storage systems that can be utilized for DR (demand response) with registered products. | Calculated based on an initial effective capacity of 1 kWh at 34,500 JPY (subsidy rate within 3/10; maximum 600,000 JPY per application). | As of May 29, 2026, the budget has been reached, and the public recruitment has ended (applications are currently not accepted). |
| National “Mirai Eco Housing 2026 Project” (Renovation) | Storage batteries are one of the eligible facilities, but they must be combined with essential works such as insulation renovation of windows (openings) and the structure; installation of storage batteries alone is not eligible. Solar panels are not included as eligible facilities. | Storage Battery: 96,000 JPY/unit | Ends as soon as the budget limit is reached. Please check the official site for application status. |
| Kanagawa Prefecture “Reiwa 8 Annual Kanagawa Prefecture Subsidy for Self-Consumption Type Renewable Energy Installation Costs” | Corporations and individuals filing blue returns (individual residences are not eligible). Solar power must have a generation output of 10 kW or more, for business facilities, and equipment not certified under FIT/FIP. | Solar: 80,000 JPY/kW, etc. Storage System: 50,000 JPY/kWh (maximum 5,000,000 JPY) |
Recruitment ended on September 3, 2026 (application amount reached the budget amount). |
As of October 6, 2026, the subsidies for Oi Town have only a few remaining planned cases, and the Kanagawa Prefecture residential subsidies have passed the application deadline for Phase 2 of Reiwa 8, while the national DR home storage battery project has also ended public recruitment. Subsidies for Nakai Town, Oi Town, and Matsuda Town require applications before construction (or installation after grant approval), and the prefectural residential subsidies require construction to begin after receiving “grant decision.” Starting construction beforehand may result in ineligibility, and applying does not guarantee a grant, so please confirm before contracting or starting construction.
Kakeru Koumuten will guide you on the eligibility conditions for each system after confirming them.
Nakai Town “Subsidy for Home Solar Power Generation System, HEMS, and Storage Battery Installation”
Nakai Town provides subsidies for individuals who install solar power generation systems, HEMS, and storage batteries in their own homes within the town. Conditions include having a lighting contract and no delinquency on town taxes, and being able to cooperate with a one-year report after applying for the Nakai Eco Monitor (environmental household account monitor). If only a storage battery is installed, it must be connected to the solar power generation system.
The subsidy amount for the fiscal year Reiwa 8 is 15,000 yen per kW for solar power (up to 52,000 yen), 10,000 yen for HEMS, and 50,000 yen for storage batteries. This system accepts applications in the order they are submitted, and items that have already been installed, purchased, or started construction are not eligible. Due to budget constraints, the application may close, so please check the town’s official page for the current status.
👉 Click here for Nakai Town’s official page
Oi Town “Subsidy for Residential Smart Energy Equipment Installation Costs”
Oi Town provides subsidies for individuals residing (or planning to reside, with resident registration at the time of subsidy completion) in the town for the installation costs of residential smart energy equipment. Conditions include having a lighting contract, the building being for residential use, obtaining the owner’s consent, and having no delinquent town taxes.
The subsidy amount for the fiscal year Reiwa 8 is 20,000 yen per kW for solar power (up to 100,000 yen), 20,000 yen for HEMS, and 50,000 yen for storage batteries. Applications will be accepted on a first-come, first-served basis starting from April 1, 2026, and as of the town’s announcement (as of August 1, 2026), there are fewer than 10 remaining for solar power and HEMS, and fewer than 5 remaining for storage batteries. You must install the equipment after receiving the subsidy approval notification, so please check the town’s official page for the latest application status.
👉 Click here for Oi Town’s official page
Matsuda Town “Smart House Development Promotion Project Subsidy System”
Matsuda Town has established a subsidy system for individuals who install eligible equipment in their own residences within the fiscal year. Conditions include having a lighting contract, obtaining the owner’s consent, and paying town taxes, and installations via lease or PPA are also eligible.
The subsidy amount for the fiscal year Reiwa 8 is 20,000 yen per kW for solar power (up to 100,000 yen), 50,000 yen for stationary lithium-ion storage batteries, and also includes HEMS (10,000 yen), home fuel cells, water heaters, V2H charging equipment, etc. The budget for the fiscal year Reiwa 8 is 3,750,000 yen, and applications are accepted on a first-come, first-served basis (mail applications are not accepted), with applications required before construction begins. Performance reports must be submitted within 30 days of installation completion or by March 15, 2027, whichever comes first.
👉 Click here for Matsuda Town’s official page
Kaisei Town “Zero Carbon City Creation Subsidy System” (Subsidy for Smart House Renovation of Existing Homes)
Kaisei Town has established a subsidy system for the installation of solar power systems, storage batteries, HEMS, etc., in existing homes in the town that are over one year old, aiming for the realization of a Zero Carbon City. Conditions for solar power include consuming more than 30% of the generated electricity for self-consumption and not using the FIT system.
According to town documents, solar power generation is up to 120,000 yen per 1kW (for the priority measure acceleration subsidy, up to 4kW; over 4kW is 70,000 yen/kW), while other installations are 50,000 yen/kW (with a cap of 200,000 yen), and there are additional allowances for installing batteries, HEMS, and three or more systems simultaneously. Applications for the Reiwa 8 fiscal year will begin on July 1, with a deadline of February 15, 2027 (for subsidies other than the priority measure acceleration subsidy, the deadline is March 15). This system is limited to the Reiwa 8 fiscal year.
👉 Click here for the official page of Kaisei Town
Yamakita Town
Regarding Yamakita Town, the town’s official site does not confirm any unique subsidy system for residential solar power generation or storage batteries. There may be applicable programs from Kanagawa Prefecture or the national government, so please contact Yamakita Town for the latest information and consultations.
National Subsidy “DR Home Battery Project (Support Project for Home Battery Systems for DR Resource Introduction)”
The national government has been implementing the “DR Home Battery Project” to support the installation of home storage batteries.
This program targets those who are introducing new registered products for storage systems that can be used for demand response (DR) adjustments. In the fiscal year 2027 supplementary budget, the subsidy amount was based on an initial effective capacity of 34,500 yen per 1kWh, with a subsidy rate of up to 30% and a maximum of 600,000 yen per application. There are conditions such as excluding contracts or orders made before the grant decision.
However, the fiscal year 2027 supplementary budget reached its application limit on May 29, 2026, and the public offering has ended (the previous fiscal year’s supplementary budget also ended on July 2, 2025). Applications are currently not possible, so please check the official site for future public offerings.
Additionally, there are currently no subsidies confirmed for the installation of solar panels on existing homes.
👉 Click here for the official site of the DR Home Battery Project
Kanagawa Prefecture “Reiwa 8 Fiscal Year Kanagawa Prefecture Residential Solar Power Generation and Storage Battery Installation Subsidy”
In Kanagawa Prefecture, subsidies are provided for those who install both “solar panels” and “storage batteries” in residential properties.
The subsidy details are 70,000 yen per 1kW of solar power generation and 150,000 yen per storage system.
For example, if you install a 4kW solar panel and one storage battery, the subsidy amount would be calculated as 4kW × 70,000 yen + 150,000 yen = 430,000 yen.
Conditions include that the storage system must be a registered product, if construction begins before the grant decision, it will not be eligible, and the application must be made by the individual (applications by contractors on behalf are not allowed). The residential property must also meet seismic performance standards. The compatibility of this subsidy with other subsidy programs may vary, so please be sure to check.
For the fiscal year Reiwa 8, the first application period (May 11 – June 30) and the second application period (September 7 – September 30, first-come-first-served) have been conducted, and the second period has reached its application deadline. For future recruitment, please check the official page of Kanagawa Prefecture.
👉 Here is the official page of Kanagawa Prefecture
Kanagawa Prefecture “Reiwa 8 Fiscal Year Subsidy for Self-Consumption Type Renewable Energy Introduction Costs” (for businesses)
Kanagawa Prefecture is also implementing subsidies for businesses that introduce “self-consumption type” facilities that use electricity generated by solar panels.
Eligible applicants are corporations or individual business owners filing blue returns, and individual residential installations are not eligible.
Conditions include that the solar power generation must have an output of 10kW or more and supply power to business facilities within the prefecture, and that the equipment must not be certified under FIT or FIP.
The subsidy amount is 80,000 yen per kW for solar power generation and 50,000 yen per kWh for the accompanying storage system (with a maximum of 5 million yen), among other conditions.
As the application amount reached the budget amount for the fiscal year Reiwa 8, applications were closed on September 3, 2026.
Businesses considering the installation of solar panels on commercial buildings in Ashigarakami District are advised to check the official page of Kanagawa Prefecture for the next recruitment.
👉 For details, click here
Solar Panel Installation & Storage Battery Installation Price List
⇧Service Menu|For Costs Related to Solar Panel Removal and Hot Water Heater Dismantling, Click Here
Breakdown of Installation Capacity, Equipment, and Construction Costs
The costs for solar panels and storage batteries should be checked separately as “Equipment Costs (Device Costs)” and “Construction Costs”.
Even for the same “Complete Solar Panel Installation,” the amount can vary significantly depending on the installation capacity, equipment grade, and roof condition.
Considerations for Installation Capacity (kW) and Battery Capacity (kWh)
The installation capacity of solar panels is determined by “Output of One Panel (W) × Number of Panels”, with the unit being kW (kilowatts). Storage batteries are compared in terms of the amount of electricity they can store, measured in kWh (kilowatt-hours).
The amount of kW that can be installed on a roof varies for each house based on the roof’s shape, orientation, and size. At Kakeru Koumuten, we create layout diagrams from blueprints and on-site surveys to present the installation capacity.
On our pricing page, we list solar panel costs as approximately 800,000 JPY to 1,200,000 JPY for 3-5 kW and 1,200,000 JPY to 1,900,000 JPY for 6-10 kW. (These are just rough estimates and can vary based on wiring length, scaffold range, existing roofing materials, panel layout, etc.)
▶ Service Menu|For Costs Related to Solar Panel Installation and Storage Battery Installation, Click Here
Items to Check in the Estimate (Cost Verification)
When comparing estimates, it is common to compare different capacities and equipment by looking only at the amounts. Please check if the following items are clearly stated in each company’s estimate!
| 1. Solar Panels | Manufacturer, model number, output per panel (W), number of panels, total installation capacity (kW) should be specified. |
| 2. Power Conditioner | Manufacturer, model number, capacity, number of units, installation location (indoor/outdoor). Also check if it is a type that controls in conjunction with a storage battery. |
| 3. Storage Battery | Manufacturer, model number, capacity (kWh), range usable during a power outage (entire house or specific circuits), installation location. |
| 4. Mounting Frame and Hardware | Name of the hardware suitable for the roofing material and the method of securing it (whether it is a method that drills holes or a method that clamps and secures). |
| 5. Wiring and Electrical Work | Wiring route and length, work around the distribution board, and whether there is a monitor to check the power generation amount. |
| 6. Roof Reinforcement and Waterproofing | Details of waterproofing treatment at the fixed parts, whether necessary roof repairs and substrate reinforcements are included. |
| 7. Applications | How much support is included for applications to the power company, certification applications for selling electricity (FIT), and subsidy applications. |
| 8. Scaffolding | Scope and quantity of scaffolding. If it is simultaneous with roof work or exterior painting, confirm that the same scope and quantity are not double-counted. |
| 9. Removal and Disposal | Whether the removal of existing solar thermal water heaters and old panels, as well as disposal costs for waste materials, are included. |
| 10. Tax Classification and Warranty | Whether it is tax-inclusive or tax-exclusive, conditions under which additional costs may arise, and the details and duration of both manufacturer and workmanship warranties. |
If the capacity differs, both the amount and power generation will change. Kakeru Koumuten Co., Ltd. warmly welcomes competitive estimates, so if you bring estimates from other companies, we will explain the differences for each item!
Self-Estimate and Profit Simulation for Solar Power Generation
With the simulator above,
you can obtain an approximate estimate and a profit simulation for up to 30 years!
If you know the total installation capacity of solar panels on the roof and the capacity of the storage battery, you can get an approximate estimate and profit simulation!
*The simulation results are approximate. Actual profits may vary based on assumptions such as electricity rates, self-consumption ratios, selling prices, and costs for equipment inspection and replacement.
Customer Voices
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customer reviews
Asao-ku, Kawasaki City | We received reviews about the ridge cap and rain gutter replacement work!
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customer reviews
Kohoku-ku, Yokohama | We received reviews about the roof overlay (cover method)!
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customer reviews
Kohoku-ku, Yokohama | We Received Reviews About Exterior Painting!
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customer reviews
Hodogaya-ku, Yokohama | We received reviews about our exterior fence construction!
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customer reviews
Tsurumi-ku, Yokohama | We received reviews about roof and exterior wall painting, as well as metalwork and rain gutter replacement work!
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customer reviews
Higashiyamato City, Tokyo | We received reviews about exterior painting and roof overlay (cover method)!
Case Studies of Solar Panel Installations
| Work Details |
| Solar Panel Installation Battery Installation |
| Existing Roofing Material |
| Horizontal Metal Roof (Super Galtect) |
| Installation Capacity |
| Solar Panel: 4.3kW Battery: 5kWh range |
| Base Mounting Hardware Used |
| Niigata Manufactured / Aluminum Catch Type Hardware |
| Fixing Method & Waterproofing Arrangement |
| Fixed by catching the horizontal metal roof with catch type hardware (Catch Method) |
| Price Range |
| 2,200,000 JPY～2,300,000 JPY *Due to the grant being provided, the actual burden amount is approximately 1,000,000 JPY Estimated recovery period for construction costs: about 8 to 9 years (self-consumption) *The grant amount and recovery estimate are based on the system and calculations at the time of construction, and may differ under the current system. |
| Construction Period |
| About 3 days |
| Completion Month |
| April 2025 |
| Inquiry Details |
| I am considering the installation of solar panels and storage batteries. I heard that grants are available, and I would like to know how much can be provided. |
Our Proposal
We visited to provide an estimate and created a layout diagram for the solar panels from the drawings!
The layout diagram shows the arrangement of solar panels on the roof.
Since we can also determine the installation capacity, it allows for power generation simulations and financial simulations.
We have also understood the expected amount of the grant, so we explained it to the customer along with the estimate!
How to Choose a Solar Panel Installation Contractor in Ashigarakami District, Kanagawa Prefecture
There are many solar panel installation contractors available in Ashigarakami District, Kanagawa Prefecture, and you may be unsure which contractor to choose.
Therefore, when requesting solar panel installation and battery installation work, let’s check the following 4 points.
● Have extensive knowledge not only about solar power but also about roofs
● Confirm the existence of warranties and aftercare maintenance
● Obtain estimates from multiple contractors (3 companies as a guideline)
● Check if they provide support for subsidy applications
By confirming the above 4 points, you will be able to choose a reliable contractor.
Have knowledge not only about solar panels but also about roofs
Improper installation of solar panels can be caused by a lack of knowledge and verification regarding roofs and waterproofing.
While knowledge about solar panels is certainly important, understanding the roof and waterproofing at the installation site of the solar panels is also crucial.
⚠︎Examples of troubles caused by insufficient verification of roofs and waterproofing
・Solar panels installed on a deteriorated roof causing leaks
・Solar panels installed on a roof with a short lifespan, requiring remodeling to detach and reattach the solar panels within a few years
・Misjudging the type of waterproofing and applying incorrect treatment, leading to leaks
and more
When installing solar panels, understanding the condition and type of the existing roof allows you to avoid unnecessary expenses and unexpected troubles.
▶ Go to “Roof Verification Before Installing Solar Panels” in this article
Confirm the existence of warranties and aftercare maintenance
When choosing a solar installation contractor, let’s confirm the existence of warranties. It is important to check not only the duration of the warranty but also the coverage, disclaimers, and cost conditions.
While the solar panels and battery themselves come with a manufacturer’s warranty, it is also important to check for the existence of a workmanship warranty in case leaks occur after installation!
For contractors that offer a workmanship warranty, if leaks occur after installation, they may be able to respond under the warranty, provided it is within the warranty period and conditions.
Additionally, some contractors offer after-sales service separate from warranties, so be sure to check if the contractor you are considering has after-sales service.
Changes or damage on the roof can occur in areas that are not visible, so there is a possibility that customers may not notice them themselves.
By conducting inspections during after-sales maintenance, we can easily prevent major repairs or failures by discovering issues early!
Kakeru Koumuten Co., Ltd. provides a leak warranty as part of the workmanship warranty for solar panel installations. (The warranty for solar panel installations is 10 years, and depending on the condition of the roof before installation, we may not be able to provide a warranty unless roof renovations are performed.)
We also conduct after-sales maintenance and send out annual DM!
Please check the DM, and if you wish, we will visit you for after-sales maintenance!
Obtain estimates from multiple contractors (3 companies as a guideline)
When requesting solar panel installation, be sure to obtain estimates from multiple contractors.
Even for the same manufacturer and the same work content, costs may vary, and warranties and after-sales services may differ.
Additionally, obtaining multiple estimates makes it easier to negotiate prices.
To request your desired contractor at a lower price, we recommend obtaining estimates from multiple contractors.
When comparing estimates, please check the following:
“Check the items in the estimate”
“Type of solar panel”
“Warranties and after-sales services”
Make sure to compare these details carefully! If the rank of auxiliary materials is low or if steps are skipped, costs can be reduced, so avoid making decisions based solely on price!
▶ Go to “Breakdown of installation capacity, equipment, and construction costs” in this article
Check if they provide support for subsidy applications
There may be subsidies available for solar panel installations and battery installations, but if the order of procedures is incorrect or if there are deficiencies in the documents, the subsidy may not be granted.
For systems like the Kanagawa Prefecture housing subsidy, where applications cannot be submitted by the contractor and must be done by the individual, it is reassuring to have a contractor that supports the preparation of necessary documents and the flow of procedures.
Be sure to complete the procedures specified for each system (for the prefectural housing subsidy, this means obtaining a grant decision) before proceeding with the construction!
For the prefectural housing subsidy, after the construction is completed, a performance report must be submitted, and the flow will be to undergo a review before the grant is issued! (The flow of procedures varies by system)
▶ Go to “Subsidies and Grants That May Be Applicable in Ashigarakami District” within this article
Benefits of Introducing Solar Power Equipment
The benefits of installing solar panels are summarized in the following 5 points!
Benefit 1: Economic Advantages
The biggest advantage of installing solar panels is the economic benefit!
While the selling price of electricity has decreased compared to ten years ago, you can benefit by reducing the amount of electricity you purchase from the utility company by consuming the electricity you generate!
As electricity costs rise, the ability to cover your consumption with solar power becomes increasingly attractive!
If you plan to use the generated electricity at night, installing a storage battery is essential!
For residential (under 10kW) selling prices (FIT), the price setting from certifications after October 2025 will be “24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year.” The same price will apply for the 2026 fiscal year. After the 5th year, it is generally more advantageous to use the electricity at home (self-consumption), making the combination with storage batteries a viable option.
👉 Ministry of the Environment | For purchase prices, periods, etc., click here
Benefit 2 : You Can Utilize Subsidies!
The conditions and amounts of subsidies vary by prefecture and municipality, but if you meet the requirements, you may be able to utilize subsidies!
Reducing the actual burden through subsidies is a significant advantage!
In Ashigarakami District, there may be programs available from the national government, Kanagawa Prefecture, and each town. Since the application status and order of acceptance differ by town, please check the official pages of each town.
Benefit 3: Environmentally Friendly!
Solar power generation has low carbon dioxide emissions and can reduce dependence on fossil fuels, contributing to the mitigation of global warming.
Solar panels themselves do not produce noise or exhaust gases during the generation process, making them an environmentally friendly power generation method (though devices like power conditioners may have operational noise).
Benefit 4: Expect Heat Insulation Effects!!
By installing the panels on the roof or rooftop, they block direct sunlight from hitting the roof.
Especially in summer, it can help reduce the temperature rise of the roof, providing a heat shielding effect!
(Note that this does not improve the building’s insulation performance itself.)
Benefit 5 Electricity can be used even during power outages!!
If a storage battery is installed, it is possible to use electricity even during emergencies such as power outages!
Even without a storage battery, if you have a power conditioner with autonomous operation capability, you may be able to use electricity from a dedicated outlet during daytime generation.
(The devices, output, and duration that can be used during a power outage vary depending on the model and wiring method.)
What points should be noted when introducing solar power generation?
Next, we will explain the “three points to note” when installing solar panels!
Point 1 Maintenance costs are incurred
A particularly overlooked maintenance cost is for the roof where the solar panels are installed.
If you perform roof remodeling 10 to 20 years later, there will be costs for removing and reinstalling the solar panels.
If the existing roof is deteriorating, it is reassuring to remodel it with durable roofing materials before installing the solar panels!
Additionally, there will be costs for regular inspections of the equipment, repairs or replacements of the power conditioner, and updates due to the deterioration of the storage battery.
It is reassuring to be able to simulate maintenance costs before introducing solar panels!
Point 2 The risk of leaks increases depending on the roofing material
The fixing methods for slate roofs and tile roofs vary by construction method, but when using screws or other fasteners to secure the roofing materials and substrate, waterproofing of the fixed areas is crucial.
If the method involves making holes in the roof, there will inevitably be a risk of leaks.
Of course, we will ensure proper waterproofing, but if you are concerned about making holes, replacing the roofing material with a metal roof and securing the solar panels using the catch method is also an option. (The catch method has compatibility conditions between the roofing material and the fasteners, and it cannot be used with all metal roofs.)
Catch-type base metal fittings for horizontal metal roofs
Note 3: The roof will become heavier
Since solar panels will be installed, the roof will become heavier. After investigating the existing roof, substrate, and load-bearing capacity, switching to a lighter roof may be one option if necessary.
How to Choose Solar Panels?
There are many manufacturers of solar panels, and their output and costs vary.
It is not simply a matter of “this manufacturer has the best solar panels”; it is important to choose solar panels that are suitable for your life plan and building!
Here are some points to consider when comparing solar panels!
Choosing Method 1: Compare by Total Output of the Roof
When installing solar panels on the roof, it is important to know how much power can be generated in a limited area, and the more power generated, the better!
Solar panels vary in size and output depending on the manufacturer.
A panel with 350W output and a panel with 400W output may seem that the one with higher output is better at first glance.
However, if the size of the panel does not fit well with the roof, there may be cases where “20 panels of 350W can be installed” and “15 panels of 400W can be installed,” leading to different installation capacities on the same roof due to the size difference.
400W × 15 panels = 6kW (total output of the roof)
350W × 20 panels = 7kW (total output of the roof)
As shown above, even if the output of one panel is lower, the total output of the roof may be higher!
It is important to consider the total output of the roof rather than the output of a single panel!
*The above is a calculation of total output (kW). The actual power generation (kWh) will vary depending on conditions such as roof orientation, slope, and shading.
Choosing Method 2: Compare by Degradation Rate of Solar Panels
Solar panels have a degradation rate, and their output gradually decreases after 10 years and 20 years.
The degree of output reduction after long-term use varies by product. The manufacturer’s output guarantee value is a standard figure for warranty purposes and does not indicate the actual degradation rate or power generation itself.
By considering the degradation rate along with the initial output, you can choose solar panels without regrets!
Choosing Method 3: Compare by Warranty Period
There are several types of warranties for solar panels, including “output warranty,” “natural disaster warranty,” and “system warranty,” and the warranty periods vary by manufacturer.
For output warranties, some manufacturers offer a 30-year warranty while others provide a 10-year warranty, so it varies!
Longer warranties are better, so be sure to check the warranty periods and conditions of the manufacturers you are considering!
Frequently Asked Questions about Solar Power and Storage Battery Installation in Ashigarakami District
We have compiled frequently asked questions from customers considering the installation of solar panels and storage batteries in Ashigarakami District. (Tap to open the answers)
How much does it cost to install solar panels and storage batteries in Ashigarakami District, Kanagawa Prefecture?
The cost varies depending on the installation capacity, equipment, and condition of the roof. In the above construction example (solar panel 4.3kW + storage battery, completed in April 2025), it was 2.2 million yen to 2.3 million yen.
Guidelines based on capacity are published on the solar panel and storage battery installation pricing page. We will create a layout diagram from the drawings and on-site survey and provide a free estimate!
Are there any subsidies available for solar power and storage battery installation in Ashigarakami District?
As of October 6, 2026, there are town-specific subsidy systems in Nakai Town, Oi Town, Matsuda Town, and Kaisei Town (we have not confirmed a town-specific system in Yamakita Town), and Oi Town has only a few remaining planned cases. The Kanagawa Prefecture subsidies (70,000 yen/kW for solar power and 150,000 yen per unit for storage batteries) are approaching the application deadline for the second phase of fiscal year 2026, and the national DR home storage battery project has ended its public recruitment. Please check each official page for future recruitment.
Since the application status may change, please refer to the subsidy and grant section and consult with us before signing a contract.
Can I apply for subsidies after the construction is completed?
In many systems, procedures are required before construction. The subsidies from each town in Ashigarakami District and Kanagawa Prefecture often require “application before construction starts” or “start of construction after grant decision,” and if you install it first, you may be excluded from eligibility. The procedures differ by town.
The order of procedures varies by system, so please confirm before signing a contract or starting construction.
Can solar panels be installed on a slate roof? I’m worried about leaks.
It is possible to install on a slate roof, but it is necessary to check the condition of the roofing material and substrate. The fixing method varies by construction method, and in methods that fix brackets to the roofing material or substrate, waterproofing treatment of the fixed parts is essential.
Kakeru Koumuten is a specialized exterior renovation company strong in roofing work, so we will check the condition of the roof before installation, and if deterioration is advanced, we can also propose methods to install after performing roof overlay (cover method) or replacement.
My roof is old. Should I do a roof renovation first?
It depends on the condition of the roof. If a roof renovation is needed 10 to 20 years after installation, the cost of removing and reattaching the solar panels will be incurred separately. If the remaining lifespan of the roof is short, renovating to a highly durable roofing material before installation may help reduce total costs.
Please consult us on how to proceed with the installation after confirming the condition of the roof during the on-site survey!
Is it better to install a storage battery together with solar panels?
If you want to use the generated electricity at night or prepare for power outages, simultaneous installation is recommended. The selling price for electricity will be 8.3 yen/kWh after the fifth year, making it more beneficial to use it in your home rather than selling it.
Additionally, the subsidy in Kanagawa Prefecture requires the simultaneous introduction of solar panels and storage batteries. Please check the official pages of each town for the conditions of subsidies for each facility. You can compare “solar panels only” and “solar panels + storage batteries” using a financial simulation.
How many kW can be installed on my roof? Is it okay for north-facing roofs or roofs with shadows?
The capacity that can be installed varies depending on the shape, orientation, and size of the roof. At Kakeru Koumuten, we create a layout diagram from the drawings and on-site survey, and provide you with the installation capacity and power generation simulation.
The Ashigarakami District has a varied terrain from the Ashigara Plain to the mountains, and the way shadows are cast by neighboring houses, trees, and mountain ridges differs from one house to another. You can check the expected power generation through the power generation simulation.
How long is the construction period?
In the above construction example (solar panel 4.3 kW + storage battery), it took about 3 days. The duration may vary if roof work is done simultaneously or depending on the shape and installation capacity of the roof.
Additionally, please note that there is a separate period required for applications for subsidies and power companies, so please consult us as soon as possible.
What is the current selling price (FIT)?
For residential use (under 10 kW), the certified price from October 2025 will be 24 yen/kWh for the first 4 years, and 8.3 yen/kWh from the 5th to the 10th year, and the same price will apply for the 2026 fiscal year.
The idea is to recover the initial costs quickly in the first four years and then focus on self-consumption. Kakeru Koumuten provides a financial simulation that takes into account loan interest rates and electricity costs.
Can you handle maintenance and inspections after installation?
Yes, we can. Kakeru Koumuten sends out annual after-service maintenance notices via DM and visits customers who request inspections. We can also clean solar panels using specialized brushes if the power generation decreases due to dirt.
Since it is difficult to check areas on the roof by yourself, please feel free to consult us if you have any concerns.
Can you also handle renovations for roofs that already have solar panels installed?
Yes, we can. Kakeru Koumuten can detach and reattach solar panels in-house, allowing us to remove the panels, perform roof overlay (cover method) or replacement, and then reinstall them consistently. The removed panels can be stored in our warehouse.
For costs, please refer to the solar panel removal and installation fee page.
If you are looking for a solar panel installation contractor in Ashigarakami District, please consult Kakeru Koumuten
Our company handles a wide range of exterior renovations, including solar panels, roof work, and exterior wall work in Ashigarakami District, Kanagawa Prefecture.
We have received requests from many customers, including renovation companies and real estate agencies, who have contacted us!
Kakeru Koumuten promises “high-quality renovations at low cost”, and we have received great feedback from numerous customers.
We continue to update our construction achievements every year and strive to improve quality to satisfy even more customers in the future.
Our company can perform all exterior renovations, not only roof overlay work and re-roofing but also partial roof repairs, exterior painting, and exterior cover methods.
We are also happy to handle small jobs like partial repairs and rain gutter cleaning!
In urgent cases like leak repairs, we may be able to provide emergency measures without setting up scaffolding, as long as safety can be ensured, so please consult us!
“I want to know about recommended solar panels”, “I want to keep costs down as much as possible”, “I just want an estimate for now”, we will provide optimal solutions for your specific requests.
We will never propose unnecessary work that prioritizes profit!
We always stand in the customer’s position and will propose the best construction plan!
We are confident that we will not be outdone in terms of cost, quality, and planning for exterior work compared to other companies!
We are confident, so we welcome competitive quotes!
Estimates are completely free, and if our company is found to be inferior to others, you are free to decline!
Characteristics of Ashigarakami District, Kanagawa Prefecture, and Points for Solar Work
Ashigarakami District consists of five towns: Nakai Town, Oi Town, Matsuda Town, Yamakita Town, and Kaisei Town. According to official documents from Kanagawa Prefecture, the Ashigara Plain is surrounded by the Nishitanzawa Mountain Range, the Hakone Outer Rim, and the Tsukahara Hills, with the Sakawa River flowing through the center. The area of each town varies, with Kaisei Town at 6.55 km², Oi Town at 14.38 km², Nakai Town at 19.99 km², Matsuda Town at 37.75 km², and Yamakita Town at 224.61 km², ranging from towns in the plain to larger towns in the mountainous areas.
We have summarized the characteristics of Ashigarakami District and points to consider when installing solar panels and storage batteries below. (Tap to open)
View the characteristics of Ashigarakami District and points for solar work
■ From plains to mountains. Sunlight and shadow vary by town
Overview of Kanagawa Prefecture (Official Prefectural Document) introduces that the Ashigarakami region is surrounded by the Nishitanzawa mountain range and the Hakone outer rim, with the Ashigara Plain spreading out. In residential areas of the plain, shadows are mainly cast by neighboring houses, trees, and utility poles, while in mountainous residential areas, shadows may change in the morning and evening due to mountain ridges, slopes, and surrounding trees. At Kakeru Koumuten, we create layout diagrams based on blueprints and the actual site conditions, allowing you to confirm through a power generation simulation.
■ Confirm installation locations for equipment in lowlands along the Sakawa River
In the Ashigara Plain where the Sakawa River flows through the center of the town, the expected flooding varies depending on your residence’s location. When deciding on the installation locations for storage batteries and power conditioners, it is reassuring to check the expected flooding for your residence on a hazard map. In mountainous or sloped areas, it is also important to confirm the relationship with slopes and retaining walls.
■ Consider fallen leaves and surrounding trees in mountainous residences
In towns like Yamakita, which have extensive mountainous areas, or in residential areas with hills and many trees, fallen leaves and branches may easily accumulate on panels and rain gutters. If dirt such as fallen leaves and dust accumulates on the roof, it may affect power generation, so it is important to consider the arrangement of panels and the ease of cleaning and inspecting the rain gutters.
■ Different subsidy application statuses and order by town
In Ashigarakami District, Nakai Town, Oi Town, Matsuda Town, and Kaisei Town each have their own unique systems, with amounts, conditions, application order, and acceptance statuses varying by town. As for Yamakita Town, we have not confirmed its unique system. It is important to check the system of your town in advance, along with the timing of the construction.
■ Check the roof condition according to the age of the building
For houses that have been built for several years, it is important to check the condition of the roofing materials and substrate before installing solar panels. Depending on the condition of the roof, installing them simultaneously with roof renovations can reduce future costs for removing and reinstalling solar panels.
Our company is based in Kanagawa Prefecture and handles many exterior construction and solar projects in Ashigarakami District.
We are happy to assist with partial roof repairs such as roof overlay work, roof replacement, and leak repairs, as well as other repairs! Please feel free to consult us about any sudden troubles!
Service Area in Ashigarakami District, Kanagawa Prefecture
Kakeru Koumuten accepts requests throughout Kanagawa Prefecture and Tokyo.
List of Areas in Ashigarakami District, Kanagawa Prefecture
Nakai Town, Ashigarakami District / Oi Town, Ashigarakami District / Matsuda Town, Ashigarakami District / Yamakita Town, Ashigarakami District / Kaisei Town, Ashigarakami District
・For exterior wall painting in Ashigarakami District, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・For roof renovations in Ashigarakami District, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・For exterior renovations in Ashigarakami District, Kanagawa Prefecture, trust Kakeru Koumuten Co., Ltd.!
・Kakeru Koumuten Co., Ltd. project achievements
・Kakeru Koumuten Co., Ltd. aftercare services
・Kakeru Koumuten Co., Ltd. construction menu and price list
・Kakeru Koumuten Co., Ltd. staff blog and announcements
・Explaining the importance of comparative estimates and key points!
・Top 12 solar power generation manufacturers! Features and selection tips included!
・What are the installation costs for solar power generation? Comprehensive tips to reduce costs!
・What are the best locations for installing solar power generation? Key points for site selection included!
・Find out more about solar power generation estimates here!
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contact Kakeru Koumuten Co., Ltd.
Kakeru Koumuten is a young company whose team is, on average, in their late twenties, but our skills are second to none.
Our greatest strength is that we handle scaffolding, roofing and painting entirely in-house. In an industry where these tasks are usually divided among contractors, our complete service simplifies project management and helps keep costs down. Above all, if a problem arises, we respond promptly.
We proudly describe ourselves as the youngest and most helpful renovation company in Kanagawa!
