Tokyo Apartment Hunting as an Expat

Apartment hunting in Tokyo is notoriously challenging for expats, and not just because of the gaijin (foreigner) stigma some landlords still hold. The listings themselves use measurement systems, calendar conventions, and terminology that differ from anything outside Japan. This guide walks you through the three calculators that will make Japanese property listings readable.

Step 1 — Convert Tsubo and Tatami to Square Meters

Tsubo Converter

Japanese apartments are measured in tsubo (坪) and sometimes in tatami (畳) mats rather than square meters. One tsubo is 3.306 m², and one standard tatami mat is roughly 1.653 m² (though sizes vary by region — Kyoto tatami are larger than Tokyo tatami). A listing that reads "25坪" is about 82.6 m², while "8畳 + 6畳 LDK" describes a layout with individual rooms measured in mats.

When comparing listings, always convert everything to square meters so you can make apples-to-apples comparisons. Japanese real estate portals like SUUMO and Homes.co.jp list floor area (専有面積, senyū menseki) in m², but room sizes within the apartment are often still shown in tatami. The tsubo converter handles both.

Step 2 — Read Lease Dates in Japanese Era Format

Wareki

Lease agreements, key money receipts, and building registration documents in Japan use the wareki (和暦) era calendar. A document dated "令和7年3月" means Reiwa year 7, month 3 — which is March 2025. You may also encounter older documents in Heisei (平成), Showa (昭和), or rarely Taisho (大正). The wareki converter lets you instantly translate any era date into the solar year you are familiar with, and vice versa when you need to sign documents yourself.

Key documents where wareki appears: - Lease contract (chintai keiyakusho, 賃貸契約書) - Residence registration (jūminhyō, 住民票) - Building construction date on property listings (affects earthquake-resistance standards) - Guarantor company forms

Step 3 — Verify Age Requirements

Age

Some guarantor companies (hoshō kaisha, 保証会社) and certain public housing programs have age requirements. A few subsidized housing schemes are restricted to residents under a certain age, or prioritize applicants above a specific age. Japanese age requirements typically use Western age (man-nai, 満年齢), but older documents or traditional landlords may reference kazoedoshi (数え年). The age calculator shows both so you can confirm eligibility without ambiguity.

Understanding the Japanese Rental System

Beyond measurements and dates, expats should know a few key terms:

Building Age and Earthquake Safety

One critical use of the wareki converter is checking building construction dates against Japan's 1981 earthquake resistance revision (shin-taishin kijun, 新耐震基準). Any building with a construction date (kenchiku-nen, 建築年) before Showa 56 (昭和56 = 1981) was built under the old, weaker code. Converting the wareki construction date to a solar year instantly tells you whether the building meets modern safety standards — a key factor in earthquake-prone Japan.