Yamaguchi · Ichinomata Onsen, Shimonoseki
Ichinomata Onsen Grand Hotel
一の俣温泉グランドホテル
An inn at Ichinomata Onsen in the hills of Toyota, Shimonoseki, famed for 'toro-toro' water — a strongly alkaline simple sulphur spring at pH 10.0, among the highest in Japan. The skin turns slippery the moment you get in and silky afterwards, and it is widely known in Yamaguchi as a beauty bath. The Honoka and Yunoka halls have indoor and open-air baths and saunas, plus reservable private baths — a round cypress tub and a square stone one — at ¥2,000 per hour. Day bathing: adults ¥1,150, children ¥600, 08:00–21:00 (last entry 20:00); note the shortened 08:00–17:00 (last entry 16:00) on Saturdays, holidays, Golden Week, Obon and New Year. A rest lounge and restaurant (11:30–15:00) allow a bath-and-lunch visit. About 30 minutes by car from Ozuki or Mine IC on the Chūgoku Expressway, or 40 minutes by bus from JR Ozuki Station. Combine with Tsunoshima Bridge, Akiyoshidai or Nagato-Yumoto. The nearby Ichinomata Onsen Kankō Hotel is a sister property.
- Price (adult)
- ¥1,150
- Hours
- 08:00–21:00 (last entry 20:00); Saturdays, holidays, Golden Week, Obon & New Year 08:00–17:00 (last entry 16:00)
- Closed
- Open daily (3 temporary closure days in July)
- Access
- About 30 min by car from Ozuki IC or Mine IC (Chūgoku Expressway); Sanden bus for Ichinomata Onsen from JR Ozuki Station, about 40 min; about 50 min by car from central Shimonoseki
- Water type
- Alkaline simple
- Tattoos
- Ask ahead
- Admission
- Day bathing adults (junior high and up) ¥1,150, children (3 to elementary) ¥600, under 3 free. The private baths 'Honoka' (a tub bath) and 'Yunoka' (a stone bath) are ¥2,000 an hour (9:00–21:00, by reservation, bathing charged separately). The restaurant serves 11:30–15:00, bathing with a meal (reserve) from ¥6,600, massage from ¥4,000 for 40 minutes. Shampoo provided, towels included. Cards accepted
- Baths
- A large onsen hotel at Ichinomata Onsen in the mountain village of Toyoda, Shimonoseki. The great baths 'Honoka' and 'Yunoka' hold an indoor bath, a rotenburo, a jacuzzi, a waterfall bath, a sauna and a plunge, and the rotenburo opens wide to the mountains. The private baths feel like separate rooms — a cypress tub bath (Honoka) and a stone bath (Yunoka) at ¥2,000 an hour by reservation. Open from 8 a.m. for an early bath, but on Saturdays, holidays and peak periods it shortens to 17:00 (last entry 16:00), so checking the times is essential. There are rest rooms, a shop, a game corner and banquet halls, and from 31 December to 3 January it is shorter still, until 14:00
- Spring water
- The Ichinomata No. 3 source at 28.6°C and pH 10.0 — an alkaline simple sulphur spring (hypotonic, alkaline, low-temperature). Its alkalinity is among the strongest in Japan; the skin turns slick the moment you enter and smooth afterwards, hence the name 'torotoro-no-yu', the slippery bath. There is a faint sulphur scent and the water is used with circulation and filtration. Indicated for atopy, diabetes, poor circulation, dry skin, chronic skin complaints and fatigue
- Access & parking
- By car 30 min from Ozuki IC or Mine IC on the Chūgoku Expressway, 50 min from central Shimonoseki, an hour from Yamaguchi city. Public transport: Sanden Kōtsū bus (toward Toyoda-machi Nishi-ichi) from JR Ozuki Station on the San'yō Main Line, 40 min, then change at the terminus to a Blue Line bus (toward Takube) for 25 min to 'Ichinomata Onsen', right there. Free parking. The sister properties, Ichinomata Onsen Kankō Hotel (¥900 day bathing) and Fujino-yu (¥500), are within walking distance, so a bath-crawl is possible
- Phone
- 083-768-0321
- Official site
- ichinomata.co.jp ↗
- Open in Google Maps
- Google Maps ↗
Essentials
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Why go
- pH 10.0 'slippery' alkaline sulphur water
- Cypress and stone private baths; from 8 am
- ¥1,150; until 5 pm on Sat & holidays
pH 10.0 — among the slipperiest strong-alkaline sulphur springs in Japan
Ichinomata Onsen Grand Hotel is a large onsen hotel standing in the valley of Toyoda, which appears after some 50 minutes of driving into the mountains from central Shimonoseki, Yamaguchi. Within the prefecture the name works almost as a byword for a beauty-skin spring, and the reason lies in the alkalinity of the water. The source is the Ichinomata No. 3 spring at 28.6°C and pH 10.0 — among the most strongly alkaline in Japan. The moment you sink in, your skin turns slick as if rubbed with soap, and after 20 or 30 minutes you can feel with your hand that the outer skin has softened and turned smooth. Add a faint sulphur scent and you have the atmosphere proper to an alkaline simple sulphur spring. The baths are divided into the great baths 'Honoka' and 'Yunoka', with an indoor bath, rotenburo, jacuzzi, waterfall bath, sauna and plunge; the rotenburo faces the mountains and opens wide, changing with the seasons. The private baths feel like separate rooms — a cypress tub bath (Honoka) and a stone bath (Yunoka), ¥2,000 an hour by reservation with bathing charged separately — and are popular because families and couples can have this rich water entirely to themselves. Hours run from 8 a.m. to 9 p.m. (last entry 8 p.m.), allowing an early bath, but on Saturdays, holidays, Golden Week, Obon and the New Year they shorten to 17:00 (last entry 16:00), and from 31 December to 3 January to 14:00. At ¥1,150 for adults it is on the high side for day bathing in Yamaguchi, but reasonable given the character of the water and the scale of the facility. Within walking distance are the sister properties Ichinomata Onsen Kankō Hotel (¥900 day bathing, private bath 'Ukifune') and Fujino-yu (¥500), so you can compare three baths in one day.
The cypress tub bath, the stone private bath, and an early-morning routine
Around 8 a.m., when there are few overnight guests, is the quietest time. Tell the front desk you want day bathing (¥1,150), take a towel and head to the changing room. A recommended circuit: wash in the indoor bath and soak 10 minutes — strongly alkaline water cleans powerfully, so avoid scrubbing or overusing soap and just wash lightly; relax in the jacuzzi and under the waterfall bath; step out to the rotenburo and spend 15–20 minutes looking at the mountains; 8–10 minutes in the sauna and a minute in the plunge; and finish with another 10 minutes indoors. At pH 10.0 your fingertips turn slick within a few minutes of entering, and afterwards the skin feels smooth as though lotioned. Metal jewellery can discolour, so take it off before bathing, and keep the water out of your eyes and mouth (strongly alkaline water irritates mucous membranes). If you want a private bath you must reserve by phone; at ¥2,000 an hour plus admission it comes to ¥3,150 per adult, and you may choose between the cypress tub bath (Honoka) and the stone bath (Yunoka). The restaurant opens only 11:30–15:00, so either time your lunch to it or use a bathing-with-meal plan (from ¥6,600, by reservation). There are rest rooms, a shop and a game corner for resting afterwards, and massage (from ¥4,000 for 40 minutes) by reservation. Notes: Saturdays, holidays and peak periods close at 17:00 (last entry 16:00); 31 December to 3 January closes at 14:00; private baths need a reservation; about three temporary closure days in July; remove jewellery; the mountain road can ice on winter mornings. Many people name Ichinomata first when asked for the best water in Yamaguchi, and combining an early bath, a private bath and a meal makes a full day of it.
Practical details and a Shimonoseki and Akiyoshidai route
Day bathing runs 8:00–21:00 (last entry 20:00); on Saturdays, holidays, Golden Week, Obon and the New Year it is 8:00–17:00 (last entry 16:00), and from 31 December to 3 January until 14:00. There are effectively no closures, though there are about three temporary closure days in July. Adults ¥1,150, children ¥600 (under 3 free), private baths ¥2,000 an hour by reservation. The restaurant serves 11:30–15:00. Access is 30 minutes from Ozuki IC or Mine IC, 50 minutes from central Shimonoseki, and 65 minutes by bus with a change from Ozuki Station. Suggested routes: (1) two days in Shimonoseki — day one in the city (Karato market, Akama Shrine, Mojikō Retro), day two an early bath at Ichinomata, then Akiyoshidai and Akiyoshidō cave and on to Yamaguchi city; (2) a bath-crawl — comparing the Grand Hotel (¥1,150), the Kankō Hotel (¥900) and Fujino-yu (¥500) on foot; (3) a private bath plus lunch — reserve by phone in the morning, an hour in the private bath at 11, lunch in the restaurant, the great bath in the afternoon; (4) half a day at Akiyoshidai — Akiyoshidō cave, the Akiyoshidai Safari Land, a bath at Ichinomata, then back to Mine IC; (5) winter — an early bath followed by a fugu set meal in Shimonoseki. Notes: weekends and holidays close at 17:00 (an early bath is best); private baths need a reservation; the restaurant serves lunch only; temporary closures in July; cash and cards accepted. Though set in the mountains of western Yamaguchi, Ichinomata Onsen draws visitors from afar on the strength of its water, and pairs well with sightseeing in Shimonoseki and Akiyoshidai to fill a day.
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.
- Last entry is 30–60 minutes before closing.
Features
Sauna & wellness
Rules & private
Mood & scenery
Price
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.
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