About · Methodology · Updated 2026-09-18

About Akiya Check

Akiya Check turns a Japanese property listing into an English risk report built from Japan's official zoning, hazard and transaction datasets. This page is the long version of "who are you and where does the data come from" — written so you can judge for yourself how much to trust a report.

Who runs it

Akiya Check is operated by Follows, a small independent publisher based in Japan that also runs Japanese-language consumer sites. We are not a real-estate agent, broker, or developer, we do not list properties, and we receive no referral fees from sellers or agents. The only revenue from this site is the report price. Legal identity and business details are on the 特定商取引法に基づく表記 (the disclosure required under Japan's Act on Specified Commercial Transactions).

The service started in September 2026. We say this plainly because "500+ reports delivered" style badges are easy to fake and we would rather earn trust by showing our method.

Where each check comes from

Every line in a report is either read from an official dataset at the lot's coordinates, or extracted from the listing text. The table shows which is which.

Check	Source	How we get it
Geocoding of the address	Geospatial Information Authority of Japan (国土地理院, GSI) geocoding	Address → coordinates. If the listing gives only a town/chōme, the report says so and the hazard checks are marked as area-level, not lot-level.
Land-use zone, building-coverage and floor-area ratios (用途地域・建蔽率・容積率)	MLIT Real Estate Information Library (国土交通省 不動産情報ライブラリ) API	Queried at the coordinates.
City-planning area division / urbanization control area (区域区分・市街化調整区域)	MLIT Real Estate Information Library	Queried at the coordinates; cross-checked against the listing text.
Flood depth, tsunami inundation, landslide warning zones, liquefaction tendency, disaster hazard districts	MLIT Real Estate Information Library hazard layers (the same designations shown on the GSI Hazard Map Portal)	Queried at the coordinates. "Not inside a designated zone" means exactly that — not "safe".
Nearby transaction prices, population trend	MLIT Real Estate Information Library (取引価格情報・人口データ)	Queried for the surrounding area to give price and demand context.
Rebuilding prohibited (再建築不可), road frontage (接道), setback, leasehold (借地権), disclosure matters (告知事項), septic tank (浄化槽), gas type, akiya-bank status, year built	The listing text	Parsed for the Japanese terms. If the listing does not mention an item, it is marked UNKNOWN and the report gives you the Japanese question to ask the agent. We never infer these from other data.
Acquisition costs, fixed asset tax	Rule-of-thumb formulas based on the listed price and standard Japanese tax rates	Clearly labeled as estimates; the actual tax uses the assessed value, which is not public.

How a score is decided

Each item gets one of four labels. The rules are deterministic — no language model decides whether a lot is 再建築不可.

• OK — the source states a condition with no known downside (e.g. freehold, public sewer, not inside a designated hazard zone).
• CAUTION — a condition that changes cost or effort but is common and manageable (e.g. septic tank, propane, pre-1981 construction, setback required, akiya-bank conditions).
• RISK — a condition that limits what you can do with the property or its resale (e.g. rebuilding prohibited, urbanization control area, disclosure matters present, inside a special landslide zone).
• UNKNOWN — the listing did not say. Unknown items are not counted as OK, and each one comes with the question to send the agent.

The overall letter (A–E) counts RISK and CAUTION items with fixed weights. It is a triage grade, not a valuation. Two houses with the same letter can be very different in practice; the point of the grade is to tell you which items to ask about first.

What the report cannot tell you

• The physical condition of the building — termites, roof, structure, wiring. Nobody can inspect a roof from a URL. Budget for an on-site inspection.
• Micro-topography. A lot 2 m above its neighbour behaves differently in a flood; the datasets are area designations.
• Whether the municipality will actually issue a permit for your plan. We report the zoning; the building department decides.
• Anything the listing hides. If a listing omits 告知事項, the report cannot know. That is why UNKNOWN items exist.
• Legal, tax, or brokerage advice. The report is desk research; contracts, registration and tax need licensed professionals.

Refund rule

If a report states a fact as OK / CAUTION / RISK and the official dataset or the listing says otherwise, we refund the full price. If we cannot produce a report from the data available, we refund the full price. UNKNOWN items are explicitly not claims and are not covered. Details are in the terms.

How the guides are written

Every guide on the Blog & Guides page cites the law or dataset it relies on (Building Standards Act articles, MLIT and GSI portals, municipal programme pages). We do not publish testimonials, invented case studies, or "expert" bylines. When a guide gives a cost range, it is a range from public sources, not a measurement we took.

Contact and corrections

Found an error in a guide or a report? Reply to your delivery email, or use the form on the home page. Corrections are noted on the page with the date.