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Koju Onsen

Name: Koju Onsen
Address: 〒378-0102 Gunma, Tone District, Kawaba, Kawabayubara, 1851 郡川場, Kawaba, Gunma, JP
Telephone: +81278-25-8695
Rating: 4.1

4.1★ · 299 Google ratings · Kawaba, Gunma · 小住温泉

Open in Google Maps Official site (Japanese)

✓ Natural hot-spring water✓ Outdoor bath✓ Rest area✓ Restaurant

Before you go

Can you bathe here?

Day visitors

✓ YesLong-running day-use bathhouse and restaurant, but the two most recent reviews (mid-2024 and March 2025) both report it closed - one for a boiler malfunction - so travelers should confirm it has reopened before visiting.stated by 20 visitors · Feb 2023 – Mar 2025

Price

¥750Adult entry was 750 yen in the most recent reviews, up from 650 yen reported in earlier 2023 visits.stated by 3 visitors · Jan 2024 – Jun 2024

Bathing arrangement

Men and women separateMen's and women's baths are separate, with one reviewer noting crowding can vary by gender and time of day.stated by 2 visitors · Mar 2023 – Jan 2024

Tattoos

Not known · call aheadno policy stated in the 36 recent reviews we read or on the facility's website

How we know this

Watch out

Day visitors

Long-running day-use bathhouse and restaurant, but the two most recent reviews (mid-2024 and March 2025) both report it closed - one for a boiler malfunction - so travelers should confirm it has reopened before visiting.

stated by 20 visitors · Feb 2023 – Mar 2025

The bath

What you’ll find

A day-use onsen and restaurant in Kawaba village known more for its food (soba, pork dishes, apple pie) and a free upstairs relax lounge with massage chairs and hammocks than for its mild, recirculated, heated sulfur-tinged spring water, though the two most recent reviews report the facility closed for a boiler breakdown.

Outdoor bath

✓ YesAn outdoor bath, usually described as noticeably milder/cooler than the indoor one, is present.stated by 10 visitors · Feb 2023 – Mar 2024

Indoor baths

1One reviewer explicitly counts one indoor bath.stated by 1 visitor · Feb 2023

Sauna

NoNo sauna is present.stated by 1 visitor · Feb 2023

Rest area

✓ YesA free second-floor lounge with massage chairs, hammocks, and sofas is repeatedly praised.stated by 5 visitors · Feb 2023 – Jun 2024

Restaurant

✓ YesA well-regarded on-site restaurant serving substantial local dishes (soba, pork, fish) and pastries is a major draw, with some visitors coming for the food alone.stated by 12 visitors · Apr 2023 – Jun 2024

The water

Free-flowing (kakenagashi)

NoThe water is recirculated rather than a true kakenagashi flow-through system.stated by 2 visitors · Feb 2023 – Jul 2023

Spring type

Simple sulfur spring / weakly alkaline simple spring (signage is inconsistent)Posted signage describes the spring inconsistently as both a simple sulfur spring and a weakly alkaline simple spring; several reviewers note the sulfur smell is faint to nonexistent.stated by 2 visitors · Feb 2023 – Jul 2023

Source temperature

27°COne reviewer cites a source temperature of about 27°C, requiring heating before bathing.stated by 1 visitor · Sep 2023

Recirculated

✓ YesConfirmed as a fully recirculated (non-flow-through) bath by two independent reviewers.stated by 2 visitors · Feb 2023 – Jul 2023

Practical

What to bring

Hair dryer

✓ YesPremium Dyson hair dryers are provided.stated by 2 visitors · Feb 2023 – Mar 2023

Guide

What visitors add

The water

The water is lukewarm — reported by nine distinct reviewers, with the outdoor bath colder than the indoor one. One reviewer estimates roughly 38°C outdoors and 40°C indoors; several frame it as good for long soaks, but one warns the outdoor bath is too cold to be warming in winter, and one skipped the outdoor bath entirely because it was cold.

stated by 9 visitors · Feb 2023 – Mar 2024

Staffing

Staffed facility with a reception desk; five reviewers describe friendly staff or good service (one saw only three people running it on a New Year weekday). Seven distinct reviewers mention receiving a small souvenir sweet/snack from staff on departure.

stated by 9 visitors · Feb 2023 – Mar 2024

Price

Adult admission was 750 yen per three reviewers in 2024; two reviewers in 2023 paid 650 yen, so the price rose between those visits. One reviewer notes children 6 and under pay 100 yen; one mentions a ski-resort flyer deal of 1,350 yen for a meal plus bath.

stated by 7 visitors · Feb 2023 – Jun 2024

The water

Sulfur smell is disputed: three reviewers report a faint sulfur scent, while two others say they could barely or not at all smell sulfur despite the listed spring type (one cites signage saying simple sulfur spring, the other concludes it is a weakly alkaline simple spring with hydrogen sulfide too dilute to smell). Two reviewers report noticeably smooth/slippery skin after bathing.

stated by 7 visitors · Feb 2023 – Mar 2024

Outdoor bath & sauna

There is one indoor bath and one outdoor bath (rotenburo) and no sauna — three reviewers describe the indoor+outdoor layout and one of them states explicitly there is no sauna. Two reviewers complain of insects in/around the outdoor bath; one found many bugs floating in the tub and the outdoor area poorly maintained (June 2023).

stated by 5 visitors · Feb 2023 – Jan 2024

Towels, soap & lockers

One reviewer paid 250 yen for a towel. One reviewer reports the men's bath stocked with shampoo, conditioner, body soap, and face wash. Two reviewers note Dyson hair dryers are provided. One reviewer warns the lockers take a 100-yen coin that is NOT returned.

stated by 5 visitors · Feb 2023 – Mar 2024

Practical