The core value of the Site is “accurate information that won’t let you down on the ground”. This page explains how we choose facilities, how we research and verify them, how often we update, and the limits you should be aware of.
1. Listing criteria
(1) Currently operating hot springs, day-bathing facilities and spas that admit non-staying visitors; (2) facilities using genuine spring water — ordinary sento bathhouses without a spring are excluded; (3) facilities confirmed closed, on long-term hiatus or no longer accepting day visitors are removed immediately. We aim for at least seven listings in every one of Japan’s 47 prefectures.
2. Research method
Prices, hours, closing days, tattoo policies and access are cross-checked in this order: 1) the facility’s official website and social accounts; 2) official municipal and tourist-association pages; 3) major travel databases (Jalan, Yukoyuko, Nifty Onsen, etc.); 4) recent visitor reports and reviews (supporting evidence only). Where sources disagree, official sources prevail; uncertain items are marked “check ahead”.
3. What the “verified” line means
The line “Verified: 2026-09 …” at the foot of each facility page shows when and against what kind of source the data was checked. It means the information was published at that time — not that nothing has changed since.
4. Update cycle
Facilities in the 30 most popular onsen towns are re-checked first; the rest are refreshed region by region on a rolling basis. Corrections from readers or facilities are applied as soon as they are verified. Large complexes with frequent price revisions and mountain facilities in winter deserve particular care.
5. Tattoo labels
We use five levels: OK / OK with cover sticker / private bath only / not allowed / unconfirmed. Where the facility’s official guidance is silent we leave “unconfirmed” and never mark “OK” on the strength of reviews alone. Admission is ultimately decided on site, so treat the label as guidance.
6. Prices
The headline price is one adult, day bathing, weekday, tax included; weekend surcharges, special-day rates and children’s prices appear in the details. Towels and loungewear are assumed to cost extra. Donation-based and free facilities are marked “donation / free”.
7. Names and translation
The original Japanese name is shown alongside each translation; English renderings follow local tourist-office and official usage. Japanese opening-hour notation is translated into each language, but idiosyncratic expressions that resist translation are kept in the original.
8. About the images
Facility images are AI-generated impressions based on the real character of each place (architecture, bath materials, surroundings) — not photographs. This avoids the unauthorised use of photos; please check the official site for the actual appearance.
9. Limits and disclaimer
Temporary closures, cleaning hours, entry limits when crowded, disasters, equipment failures and price revisions are not reflected in real time. For small community baths, seasonal facilities and remote mountain or island sites in particular, we strongly recommend phoning ahead. The disclaimer in the Terms of Use applies to loss arising from errors.
10. Reporting a correction
If you spot an error, e-mail [email protected] with the facility name, the item that is wrong and the correct information (with a source URL if possible). We normally update within 2–3 business days and will let you know the outcome.
Last revised: 2026-09-25