Gunma · Manza Onsen
Manza Onsen Yunohana Ryokan
万座温泉 湯の花旅館
At 1,800 m in Manza Onsen — said to have the highest sulphur content in Japan — this is the most rustic of the old spa-cure inns. The wooden bathhouse holds just one indoor tub per gender, but the milky acidic sulphur water is thick and hot enough to leave you drowsy afterwards. It is known for its 'Sarunokoshikake-yu', in which extract of a bracket fungus has long been added to the water. Day use 10:00–16:00, ¥700 for adults, towels sold for ¥250. For onsen fans who want an old-school cure-bath feel amid Manza's big resort hotels. The building has tilted due to ground subsidence, so phone ahead to confirm it is operating. About 40 minutes by bus from Manza-Kazawaguchi Station.
- Price (adult)
- ¥700
- Hours
- 10:00–15:00
- Closed
- Irregular (check ahead)
- Access
- About 40 min by Seibu bus from JR Manza-Kazawaguchi Station to 'Manza Onsen', then 3 min on foot; about 90 min by car from Usui-Karuizawa IC (Manza Highway toll)
- Water type
- Sulfur spring
- Tattoos
- Ask ahead
- Admission
- Adults ¥700 / children (3 to elementary) ¥500. Towels sold (bamboo-fibre face towel ¥500, bath towel ¥1,580) — bring your own. Hours and closures vary; phone ahead (0279-97-3152)
- Baths
- Gender-separated indoor baths plus the mixed rotenburo “Tsukimi-iwa” — a rock pool ringed by dwarf bamboo under a wide sky. Speciality “Saru-no-koshikake-yu”: a bath infused with the medicinal bracket fungus, said to be the only one in Japan. Rustic mountain-lodge feel; facilities are old
- Water
- Acidic sulphur spring (described as radium-bearing), ~73 °C at source, pH 2.5, 100 % free-flowing. Colourless when it emerges, turning milky on contact with air and shifting hue with the weather. So acidic it needs no chlorine
- Parking
- Free. Highest spot in the Manza village, a few minutes’ walk from Manza Prince Hotel and Nisshinkan
- Phone
- 0279-97-3152
- Open in Google Maps
- Google Maps ↗
Essentials
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Why go
- Rustic cure inn at 1,800 m
- Thick milky sulphur bath with fungus extract
- ¥700 day use; towels ¥250
Manza’s mountain lodge “closest to the stars” — Japan’s only bracket-fungus bath
Yunohana Ryokan is one of the seven or eight inns in Manza, standing at the very top of the village — a rustic mountain lodge in contrast to the big Prince hotels. The lobby, with its stuffed tanuki and bear pelt, keeps the old alpine-hut mood; the facilities are dated but the water is intensely Manza: an acidic sulphur spring at about 73 °C, pH 2.5, 100 % free-flowing, colourless as it emerges, turning milky in the air and shifting colour with the weather. Its speciality is “Saru-no-koshikake-yu”, a bath steeped with the medicinal bracket fungus, said to be unique in Japan and claimed to amplify the sulphur spring’s effects. The mixed rotenburo “Tsukimi-iwa” is a rock pool in dwarf bamboo under a wide sky — a quiet hidden gem for starlit bathing at 1,800 m. Day bathing costs ¥700, but hours and closures vary, so phoning ahead is essential. Ground subsidence was reported in 2025, yet the inn remains open.
Tips & cautions
- Nominally 10:00–15:00 but variable — always phone (0279-97-3152).
- The rotenburo is mixed; no wrap rule stated — check whether a towel is acceptable.
- Old facilities, minimal toiletries; not for those expecting polish — a lodge for lovers of faded charm.
- pH 2.5: stings cuts and eyes, tarnishes silver.
- 1,800 m altitude, 2 m+ of snow in winter — snow tyres or chains essential.
- Bring cash.
Getting there
Seibu Kanko bus ~40 min from Manza-Kazawaguchi Station (JR Agatsuma line) to “Manza Onsen”, then 5–7 min on foot (Hoshimata 2401, Tsumagoi-mura). A few minutes’ walk above Manza Prince Hotel and Nisshinkan at the top of the village. Manza Highway bus from Karuizawa Shinkansen station. By car ~1 h 40 min from Usui-Karuizawa IC; free parking.
Before you go
- No official tattoo policy is published — ask at reception.
- Ryokan day-use hours are limited and may be suspended in peak season — phone the same morning.
- Payment is usually by ticket machine in cash — bring coins.
- Last entry is 30–60 minutes before closing.
Features
Mood & scenery
Price
Who with
Convenience
Amenities
✔ Verified operating: 2026-09 Operating status and rates cross-checked against the official site and onsen guides (full source notes in Japanese on the JA page)
Prices and hours change. Check official sources before visiting.
More in this area
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A 10-minute walk west of Kusatsu's Yubatake, at the far end of Sainokawara Park, lies one of Japan's largest open-air baths. Around 500 m² of pool brims with strongly acidic water, open to the surrounding forest. Snow in winter, fresh green in summer, illuminations at night. There are no washing stations — this is purely for soaking.
Otakinoyu
A large day facility where you can try Kusatsu's traditional 'awase-yu' — a row of wooden tubs at rising temperatures, entered in order. Indoor baths, rotenburo, sauna, plus rest and dining areas make it good for half a day. About 10 minutes' walk from the Yubatake, or a short bus ride. Admission ¥1,200 (2026); three-bath pass with Gozanoyu and Sainokawara ¥2,100.
Gozanoyu
Right in front of the Yubatake, a wooden recreation of the Edo–Meiji communal baths. Wood and stone bath halls alternate between men and women daily, with two sources (Yubatake and Bandaiko). The upstairs hall looks down on the Yubatake.
