Twelve lukewarm springs across Shizuoka, from a 1910 toji ryokan in Hatake to the Umegashima mountains, collected as digital stamps in the onsen association's summer rally.
14 places
This season ended on September 30, 2026
Earn this badge
ぬる湯スタンプラリー (Nuruyu Stamp Rally) is a seasonal rally across the lukewarm springs of Shizuoka, run by the prefecture's onsen association. Nuruyu (ぬる湯) is their word for a bath close to body temperature, which the association pins at roughly 36 to 39°C, instead of the usual scalding heat. It is the slow food of Japanese bathing: you stay in for an hour rather than three minutes, the minerals work quietly, and where the spring already rises that warm, nothing has to be heated at all. On a hot day it is the most refreshing bath there is.
The 2026 rally, subtitled 夏の陣 (Natsu no Jin, "the summer campaign"), runs from July 7 to September 30, 2026, and is the association's first fully digital edition. Stamps live in TIPS (Tourism Information Platform of Shizuoka), the prefecture's official tourism app, so there is no paper card to lose.
One thing worth knowing before you start, because it is how people lose a rally: your stamps live in the browser that opened the page. Private browsing keeps no record, clearing cookies wipes the history, and a different browser or phone shows an empty card. If that happens the fix is to reconnect to the rally from TIPS, which restores them, so always enter through the app rather than from a bookmark.
No entry or certification fee is listed for 2026, so beyond the usual bathing charges the rally costs nothing. There are two finish lines.
The roster grew mid-rally. Two Umegashima baths joined the original twelve under the banner 「梅ヶ島温泉から緊急参戦!」: 梅ヶ島新田温泉 黄金の湯 and コンヤ温泉 大野木荘, taking the set to fourteen. The completion tier did not move with it: it is still twelve stamps, now drawn from fourteen, which means two of the fourteen can be missed.
Everyone who reaches six baths gets ぬる湯サンクスクーポン2026 (Nuruyu Thanks Coupon), a sheet of discounts donated by member facilities:
Six stamps also enter you in a draw, five winners for each prize:
Collect twelve of the fourteen (全14施設の中の12施設, in the association's wording) and you get ぬる湯パスポート2026 (the Nuruyu Passport) plus an original certificate of completion. The passport is a booklet of free-bath perks put up by the members:
And a second draw:
The prize form is a Google Form the rally links to, and it closes on Friday, October 9, 2026. Everything happens after that date: the draws are made once applications close, and winners are announced only by the parcel turning up. The organisers add a practical warning, which is easy to trip over with a digital rally: your completed stamp screen disappears once the deadline passes, so screenshot it first if you want to keep it.
If a member is shut for the day or has a bath down for maintenance and you cannot get its stamp, the office can arrange a substitute or relax the completion requirement at their discretion. Worth asking rather than writing off the set.
The association also posts a printable 12湯チェックシート (check sheet, PDF) on the rally page: one line per bath for the date you soaked and what you made of the water, for anyone who likes a record outside the app. It is named for the twelve-bath target rather than the roster size.
Rally office (ぬる湯スタンプラリー事務局), inside the Shizuoka Prefecture Onsen Association: 054-221-3281, weekdays 10:00 to 16:00, [email protected].
The roster spans the whole prefecture, and the variety is the point. The temperatures below are the association's own figures.
The association's pitch is simple: lukewarm bathing is what onsen culture looks like in the heat. Where the spring itself rises lukewarm, you soak in the source exactly as it comes, with no heating and no boiler, which is also the most energy-honest way to run a bath. Long soaking is where the rest of it comes from as well: the association talks about relaxation, warmth that stays with you afterwards, and a bath you can take season after season without fighting the temperature. Shizuoka has one of Japan's richest concentrations of these springs, from the Hatake Onsen recuperation area to the 30-degree pools of the Shizuoka City mountains.
The rally is seasonal and changes shape year to year. The 2025 edition, しぞ〜かぬる湯温泉スタンプラリー, ran from August 29 to October 31 with eleven baths and a paper flyer that facility staff stamped by hand. Certification cost ¥500, and finishers ordered a keepsake carrying the rally's Nuruyu Neko (ぬる湯ネコ) cat mascot: a 56 mm can badge for ¥300, a 53 mm acrylic keyring for ¥500, or a 20 cm microfiber handkerchief for ¥1,000, each in a choice of three illustrations, plus a certificate with their name on it. Fourteen people finished all eleven.
For 2026 everything moved into TIPS, and the roster was reshuffled: five baths carried over, six sat out, and seven joined, including the first foot bath in the set. Two more came in partway through the summer, taking it to fourteen. Onsen Oni tracks the current roster on this page.
The Nuruyu Lover (Shizuoka) badge is awarded by Onsen Oni moderators once you've collected twelve stamps of an edition, the association's own completion mark. For the 2026 summer edition that means twelve of the fourteen. A screenshot of your completed stamp screen in the TIPS app, sent through the feedback channel, is enough (and you need that screenshot for yourself anyway). The rally returns in new seasons, and so does the badge: it is repeatable per edition.