Chiba · Kujūkuri / Shirako Onsen
Shirako Onsen Hotel Tokaiso
白子温泉 ホテル東海荘
An inn at Shirako Onsen, the only hot-spring area on Kujukuri Beach. Golden, iodine-rich water; day bathing from 12:30 to 17:30 costs just ¥600.
- Price (adult)
- ¥600
- Hours
- 12:30–17:30
- Closed
- Dec 30–Jan 3 (no day bathing)
- Access
- ~20 min by bus from JR Sotobo Line Mobara Sta. (Nakazato-Kaigan stop); just off Chosei IC
- Water type
- Simple spring
- Tattoos
- Ask ahead
- Spring
- An iodine-rich chloride spring, faintly yellow and known as the golden bath; said to be excellent for moisture.
- Admission
- Day bathing ¥600 (tax included). Bath towel ¥100; bath towels are not rented out.
- Hours
- 12:30–17:30. Use may be refused when busy, and day bathing is not offered 30 December to 3 January.
- Phone
- 0475-33-2061
- Official site
- tokaiso.com ↗
- Open in Google Maps
- Google Maps ↗
Essentials
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Why go
- The only onsen area on Kujukuri Beach
- Iodine-rich golden water
- Day bathing for ¥600
Shirako Onsen, the only hot spring on Kujukuri Beach
Shirako Onsen sits near the middle of Kujukuri Beach and is said to be the only hot-spring area along it. It draws brine rising with natural gas from 2,000 metres underground, low in magnesium and rich in iodine compared with seawater. Hotel Tokaiso is an inn of that spa area and also accepts day bathers.
Points for day visitors
Day bathing is limited to 12:30–17:30 and costs ¥600. A bath towel can be bought for ¥100, but as bath towels are not rented, bring a large towel of your own. Day bathing is suspended over the New Year, so check before visiting. Parking is provided about 80 metres from the inn.
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
Baths
Price
Who with
Convenience
Amenities
✔ Verified operating: 2026-10 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
Yoro Valley Goriyaku-no-yu
A day-use-only onsen on the Otaki side of Yoro Valley on the Boso Peninsula, near Awamata Falls. A rotenburo looking over wooded hills and a timber indoor bath hold the dark-tinted alkaline water typical of Boso. Popular after hikes and waterfall walks; towel and robe rental mean you can come empty-handed. Closes early at 18:00; Wednesdays off.
Kameyama Onsen Hotel
About 70 minutes from central Tokyo via the Aqua-Line, a hot-spring inn founded in 1950 on the shore of Lake Kameyama in the Boso hills. Its chocolate-brown 'kuroyu' bicarbonate water — billed as Boso's finest beauty bath — flows freely into a large bath with lake and forest views. Day use 11:30–18:00, ¥1,000 on weekdays; no day bathing Thursdays and Fridays. In autumn pair it with a foliage cruise on the lake.
Spa & Resort Kujūkuri Taiyō no Sato
One of the Bōsō peninsula's largest spa resorts, in Shirako on Kujūkuri Beach. Soak in iodine-rich, tea-coloured Chōsei spring water in the open-air bath, with seven rock-bath rooms, saunas, nap lounges, banquet halls and lodging on site. Open straight through from 10:00 to 08:00 the next morning; stays past 01:00 incur a late surcharge. Free shuttle from JR Mobara Station (reservation required). ¥1,600 weekdays, ¥1,900 weekends. Tattoos—including stickers and paint—are strictly refused.
