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Kawarayu Oyu Hotspring

川原湯温泉 王湯かわらゆおんせん おうゆ

Public Bathhouse
Kanto·Gunma

Day Use

Yes
10:00–18:00

Closed Jan 1 to 3, Jan 20 (the day of the Yukake Matsuri festival), and the 3rd Thursday of each month.

¥500

Adults 500 yen, children (elementary school age and under) 300 yen. Stay is limited to 2 hours.

Bathing & Water

Natural onsen water

Uses natural hot spring water

Outdoor BathYes

Open-air outdoor bath

Indoor BathYes

Enclosed indoor bathing area

SaunaNo

Dry heat sauna room

Capabilities

Mixed BathingNo

Shared bathing area for all genders

Gender-separated baths; bath name rotates (e.g. 不動の湯) between men's/women's sides, no mixed bathing mentioned anywhere.

Policies & Services

TattooNo

Allows entry with visible tattoos

KidsYes

Welcomes children and families

Discounted admission for elementary-school-age and younger children.

DiningNo

Restaurant or dining open to visitors (not just hotel meal plans)

WashingYes

Shower, wash stations, soap and shampoo provided

TowelsNo

Towels available to rent or borrow

No rental or loan: towels are sold at the counter (300 yen incl. tax).

Rest AreaYes

Relaxation space for after bathing

ParkingYes

On-site or nearby parking available

Views

Lake
Mountains

About

Oyu (王湯) is Kawarayu Onsen's communal bathhouse: one indoor bath and one outdoor rotenburo, no sauna, no restaurant, just a soak and an upstairs rest room. The water is clear with a faint sulfur scent, and yunohana (湯花) flecks sometimes appear. The outdoor bath faces the Yanba dam lake (八ッ場ダム) and the hills around it through the trees, though the view can be hidden depending on the season. The spring's history goes back more than 800 years to its discovery by Minamoto no Yoritomo, and it was long used as an agariyu (上がり湯), a milder finishing bath for Kusatsu bathers after Kusatsu's harsh, acidic water. In July 2014 the whole village moved uphill when the Yanba Dam flooded the old valley, and Oyu was rebuilt at the new townsite with pieces of the old building kept at its entrance. The town still holds the Yukake Matsuri (湯かけ祭り), a hot water throwing festival, here every January 20. Judo's founder, Kano Jigoro, is said to have loved this onsen too.

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Lucy (Leetah) Wakizawa

8 months ago

Brief backstory: this is one of those rare cases where my phone died from constantly photographing the surrounding beauty right before reaching this onsen - an incredibly scenic one. So you'll have to take my word that it's just very, very beautiful, and only the torrential rain and the need to return the rental car by evening forced us to cut our visit to just a couple of hours on higaeri. Location: right next to JR Kawarayu Onsen station. We specifically stopped here on the way from Kawanaka for higaeri before heading back to Tokyo. About 3 hours from Tokyo by public transport or roughly the same by car. Higaeri: yes, 500 yen, 2 hours. Crowds: fair amount. Locals, hikers, campers. Shampoo, soap: provided. Towels: can buy a small one, no bath towels. Tattoos: Japanese-language info says it's not tattoo-friendly. I covered my tattoo with a towel out of respect for the concerns of the grannies, women, and children. Milk: no. Vending machines: yes. Rest room upstairs with beautiful views of the lake and mountains. Baths: gender-separated, indoor and rotenburo with forest views. Water: very. very. hot. Need to read more about the water type on their website. Fun fact: January festival of water-splashing. If I gather photos from friends and remember anything else interesting, I'll add it. Website: http://www.kawarayu.jp/ouyu.html

Onsen Oni

Last updated July 16, 2026