Hot springs · for onsen and sento regulars
Yulog is a stamp book for people who make the rounds of onsen, sento, and thermal baths. You type the name of the bath you visited, and the moment you save, that bath's stamp lands on a paper page with the date pressed in underneath. Every bath that is new to your book moves you up an unofficial rank ladder, from Nyuto at your first bath to Yukyaku at 88, and a stamp rally you are walking can be copied in so it fills from your own entries. The book stays on your phone, with no account and no network connection.
Type the name of the bath you just left; that is all a visit needs. Press the stamp and it comes down onto the page with bleeding ink and a heavy haptic tap, the date pressed in underneath. Every bath gets its own stamp, and the book fills six to a page.
Rank counts unique baths, not visits. One bath makes you Nyuto, eight make you Shodan, and every eight after that adds a dan, up to Yukyaku at 88. A new rank arrives with a short seal ceremony you can tap to skip, and the Rank tab shows how many baths are left to the next one.
List a rally's target baths, or just set how many baths it takes. Yulog suggests matches from your entries and links one only when you confirm, and a bath whose name doesn't line up you tick off by hand. Every rally screen is labeled as not officially affiliated.
A paper stamp book has two weak spots: forget it at home and you miss the stamp, lose it and every page goes with it. Yulog keeps the book on your phone. The name of the bath is the only thing a visit needs. The date starts at today, and a photo, a one-line note, and a type (onsen, sento, or thermal bath) are there if you want them.
The stamp is drawn by the app rather than picked from a gallery. Each bath name maps to one of four frames and one of four motifs, steam, a noren curtain, ripples, or a mountain, with a slight tilt, ink speckles, and worn edges where the paper shows through. The same bath always gets the same stamp, so a place you keep going back to looks familiar on every page. Pages hold six stamps in a two-by-three grid on a paper-textured sheet with a stitched binding, and the book opens to the newest page.
The ladder has twelve rungs: Nyuto (入湯) at one bath, Shodan (初段) at eight, 2nd Dan through 10th Dan every eight baths after that, and Yukyaku (湯客) at 88. Only different baths count. A second soak at your usual sento adds a stamp and a visit, but the rank stays where it is. Extra spaces, capital letters, and full-width versus half-width characters are ignored when names are compared, so the same bath typed two ways still counts once.
Rank is worked out again from what is in the book every time something changes. Delete an entry, or merge two spellings of one bath, and the rank can go down. Earn it back and you simply get the stamp, because the promotion ceremony plays only the first time you reach a rank. Restoring a backup does not replay a stack of ceremonies either.
From the Rank tab you can open a certificate card with your book's name, your count of unique baths, your rank, and the date. It is marked UNOFFICIAL on its face and can be shared as an image.
Onsen towns and regions run paper stamp rallies, each with its own booklet. Yulog carries no official rally data; you add the rallies you are walking yourself. Give one a name, then either list its target baths, one per line, or set a number of unique baths to reach, counted from the day you add the rally. Quick-start presets cover generic 8, 10, 26, and 88-bath pilgrimages.
When a target looks like a bath already in your book, the rally asks, Is this the one? Link it or turn it down, and a suggestion you turned down does not come back. Names on a rally sheet rarely match what you typed after your soak, so a bath you tick off by hand always counts. Finishing a rally presses a small completion seal, and every rally screen carries the line Not officially affiliated, for your own records.
Visits from before you had the app go in the same way. Set the date back and the stamp still lands; only future dates are blocked. Your recent and favorite baths sit as one-tap chips at the top of the form. Tap any stamp to see its photo, its note, and every visit to that bath, and edit or delete the entry from there. Rank and rallies are recalculated each time.
The bath register lists every bath you have logged with its visit count and latest visit. A bath's own page shows first and latest visits, a favorite toggle, and a way to fix its name. Fixing a typo into a name that already exists merges the two, after a warning that your rank may drop. The Rank tab also keeps a plain tally of stamps, unique baths, visits this year, and counts by type. There are no streaks and no reminders.
Yulog has no servers and no account, and it makes no network requests, so it behaves the same in a mountain valley with no signal. Photos are optional. The app opens your photo library only when you choose to attach one, keeps a downsized copy on the phone, and every feature works without it.
For a new phone, export the whole book as one JSON file from Settings and import it on the other side. Photos are not part of the backup, and Settings says so next to the button. Delete all data empties entries, stamps, rank, rallies, and photos in one step.
Yulog records where you soaked and when. There is no facility guide, no map, no reviews, and no timer for how long you stayed in the water. The ranks and the certificate belong to this app's book alone.
Yulog is an unofficial personal stamp book. It is not affiliated with 御湯印 (Goyuin), Kyushu Onsendo, Beppu Hatto Onsendo, or any local stamp rally, and its ranks and certificate are not official certification of any kind.
No. Yulog is an unofficial personal stamp book with no connection to 御湯印 (Goyuin), Kyushu Onsendo, Beppu Hatto Onsendo, or any local rally. Its ranks and certificate exist only inside the app, and the certificate is marked UNOFFICIAL.
Yes. Set the visit date back when you log it and the stamp lands just the same. Only future dates are blocked, and your rank is worked out again from everything in the book.
No. Rank counts unique baths. A repeat visit adds another stamp and shows up in that bath's visit count, but the rank only moves when you log a bath that is new to your book.
Yes. The app makes no network requests at all, so nothing changes when you are out of range.
Export the book as a JSON file from Settings, then import it on the new phone. Entries, stamps, rank, and rallies come across. Photos are not part of the backup.
No. The app is free with no ads and no in-app purchases.
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