Build a property due-diligence data room

When you evaluate a Japanese property for redevelopment or renovation, the single most common mistake is treating the search for records as a one-stop query. Japanese real estate records are not stored in a single national database. They are fragmented across local Legal Affairs Bureaus (法務局), municipal planning departments, and archived corporate registries. A due-diligence data room is not a folder of PDFs; it is a structured evidence system that lets you trace ownership, leases, planning history, structural condition, finance, and correspondence in a way that can be audited later.

The core principle: preserve an auditable trail

Every document you collect should be traceable to a named official source, a date of issue, and a professional who can be held accountable for its interpretation. You are not the expert; your job is to assemble evidence and route each question to the appropriately licensed professional. If a document contradicts another, record the conflict and the resolution. Never assume the most recent document is correct, it may be a draft, a duplicate, or a later correction to an earlier error.

Start with the parcel, not the structure

The unit of analysis is the land parcel (土地), not the building address. Japanese records are organised by parcel, so you must identify the parcel first.

Obtain the parcel number (地番) and the land classification (地目) from the fixed-asset tax register (固定資産税台帳) or the most recent property tax notice. The tax notice lists the parcel identifier and the assessed value, but it is not a legal proof of ownership.
Obtain the cadastral map (地図) from the local Legal Affairs Bureau (法務局). The map shows parcel boundaries, road frontage, and adjacent land. Older rural maps may have positional errors of several metres; treat the map as a starting point, not a legal boundary.
Obtain the land register (登記簿) for each parcel. The register shows the current owner, the chain of previous owners, mortgage holders, easements, and any entry noting a pending filing or a court order.
Cross-check the cadastral map against the land register. A mismatch between the mapped boundary and the registered area is common and must be resolved by a licensed land and building surveyor (土地家屋調査士) before you rely on either figure.
Request a fixed-asset tax certificate (固定資産税評価証明書) from the municipal tax office. The assessed value is usually 50-70% of market value and is not a price proxy. Use it only to confirm the parcel is recorded and to identify the current owner on the municipal roll.

What you are actually researching

Japanese property information is not a single central database. The official land register (登記簿) is maintained by the Legal Affairs Bureau (法務局), but cadastral maps are held separately, municipal planning documentation sits with the local government planning department, and building confirmation applications are filed with the local authority that issued the permit. There is no unified national portal for private use. You must assemble material from at least four sources: the Legal Affairs Bureau, the municipal planning office, the tax office, and, for inherited property, the family registry (koseki, 戸籍). The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) publishes national land-use and zoning datasets, but the authoritative parcel-level record remains the local registry and cadastral map.

The core workflow

The method below assumes you are assembling a data room for a single property. It works whether you are buying, renovating, or evaluating a redevelopment site. It is not a legal opinion; it is a research and filing procedure.

Step 1: Define the choice you are making

Before collecting anything, write down the choice the data room must support. A purchase needs different evidence than a demolition, and a renovation needs different evidence than a tenant-relocation assessment. This step determines which records are essential and which are optional.

For a purchase, the question is: can this parcel be legally and physically developed as intended, and are there any ownership or encumbrance issues that would block transfer? For a redevelopment project, the question is: what is the maximum buildable volume under current zoning, and what leasehold or tenancy rights must be terminated? For an inheritance, the question is: who are the legal heirs, and what is the current registered ownership state?

Write the decision rule as: “For each record type, ask: Does this document affect title, permitted use, physical condition, or cash flow? If yes, include it. If no, file it in the correspondence folder.”

Step 2: Scope the parcel

Define the property boundary, the purpose of the investigation, and the deadline. Use the cadastral map (地図) to identify the parcel, the land register (登記簿) to confirm the current owner and legal description, and the urban planning map (都市計画図) to confirm the zoning district. The three records must match; if they do not, stop and resolve the discrepancy before proceeding.

Step 3: Gather the core records

Collect the ownership chain from the land register (登記簿) at the Legal Affairs Bureau, obtain the cadastral map and the building plan from the municipal building department, and request the fixed-asset tax record from the local government. For redevelopment projects, also obtain the redevelopment plan and the minutes of the urban redevelopment committee. For tenancy and relocation issues, obtain the lease agreement, the rent ledger, and any notices under the Land and Building Leases Act.

Step 4: Verify and file

Organise every document into the ten building blocks of the data room. Log each inquiry, answer, and resolution in a dated correspondence file. Maintain a version control table that tracks document versions, dates, and reviewers. Attach signed notes from licensed professionals confirming what was checked and what remains open.

Core ownership records (登記)

The 登記 (registration) system in Japan is maintained by the Legal Affairs Bureau (法務局). The key document is the 登記簿 (land register). It contains the parcel’s identifier, current and past owners, mortgages, easements, and other encumbrances. The register is divided into three parts: the header (表題部), the ownership section (甲区), and the rights section (乙区). You can obtain a copy at any Legal Affairs Bureau office or online via the Registration Information System. The register is parcel-specific, so you need the land’s parcel number (地番) and its administrative address (所在).

The cadastral map (地図) is a separate official record. It shows parcel boundaries, but it is not a legal description of ownership. Boundary lines on the map can be approximate, especially for older surveys. A licensed land and building surveyor (土地家屋調査士) must verify boundaries before you rely on the area figure in a redevelopment calculation. The land register and the cadastral map are maintained by the Legal Affairs Bureau but are not the same document; a discrepancy between them is common and must be resolved with a boundary survey.

The koseki (戸籍) is the family registry used to trace inheritance chains. For property due diligence, the koseki matters when a parcel has passed by inheritance and the registered owner is a deceased person. A judicial scrivener (司法書士) can obtain the necessary certificates and prepare the inheritance registration. Land and Building Surveyors (土地家屋調査士) handle boundary surveys and cadastral map corrections. A real-estate appraiser (不動産鑑定士) produces formal valuations for financing or dispute resolution. These three licensed roles are the core professional team for a Japanese property transaction; a general attorney is usually not required unless litigation or title disputes arise.

The ten building blocks of a data room

Land register (登記簿), The authoritative record of ownership, liens, and restrictions.
Cadastral map (地図), The official parcel-boundary map, often digitised but not fully integrated with the land register.
Building confirmation application (建築確認申請), The official record of approved construction plans and compliance checks.
Urban planning map (都市計画図), Shows zoning, road plans, and public facility reservations.
Fixed asset tax register (固定資産税台帳), Municipal record of assessed value and structure details.
Koseki (戸籍), Family registry for inheritance chains.
Lease agreement and building management records, Private contracts that may override registered terms.
Correspondence log, A dated record of every inquiry, answer, and resolution during due diligence.
Version control table, A structured register of document versions, dates, and reviewers.
Professional review notes, Signed notes from licensed professionals confirming what was checked and what remains open.