Right Onsen › Gunma › Kusatsu
Kobushi-no-Yu (Bandaiko Source)
4.4★ · 157 Google ratings · Kusatsu, Gunma · こぶしの湯（万代鉱源泉）
✓ Natural hot-spring water✓ Free-flowing source water
Before you go
Can you bathe here?
Day visitors
Limited hoursNon-residents can generally bathe only outside a cleaning block (roughly 9:00-11:30) and a residents-only evening block (roughly 15:00-21:00); the bath was fully closed to outsiders for an extended COVID-era period that one reviewer reports only lifted around July 2026, and old warning signage sometimes still causes confusion.stated by 10 visitors · Sep 2023 – Aug 2026
Hours
11:30–15:00from the facility listing
Price
FreeFree to enter, like other Kusatsu community baths; a voluntary donation box is provided for the residents who maintain it.stated by 3 visitors · Dec 2023 – Dec 2024
Tattoos
Not known · call aheadno policy stated in the 33 recent reviews we read or on the facility's website
Watch out
Day visitors
Non-residents can generally bathe only outside a cleaning block (roughly 9:00-11:30) and a residents-only evening block (roughly 15:00-21:00); the bath was fully closed to outsiders for an extended COVID-era period that one reviewer reports only lifted around July 2026, and old warning signage sometimes still causes confusion.
stated by 10 visitors · Sep 2023 – Aug 2026The bath
What you’ll find
A small, free, kakenagashi community bath in Kusatsu using the extremely acidic Bandaiko source, tucked away from the town center with no parking of its own; access for non-residents is time-limited and has fluctuated between fully banned (COVID-era through early 2026) and open during set daytime hours.
Indoor baths
1A single small indoor tub holding about 3 adults.stated by 2 visitors · Mar 2024 – Apr 2025
The water
Free-flowing (kakenagashi)
✓ YesGenuine kakenagashi water direct from the Bandaiko source.stated by 2 visitors · Aug 2025 – Jul 2026
Spring type
Extremely acidic (Bandaiko source)Extremely acidic Bandaiko-source water, clear but noticeably sour-tasting.stated by 2 visitors · Aug 2025 – Apr 2026
Bath temperature
43°CUsually around 42-43C, but temperature varies notably by time of day; one visit measured a scalding ~50C at the tap.stated by 4 visitors · Jun 2023 – Jul 2026
pH
pH 1.2Extremely acidic, pH 1.2, among the lowest of Kusatsu's sources.stated by 1 visitor · Apr 2026
Guide
What visitors add
The water
The water runs hot and the temperature varies: measured/estimated at 43°C tub with 49°C inlet (one reviewer), ~42°C (two reviewers), and near 50°C on an unusually hot day (one reviewer, told by residents that day was exceptional); one reviewer says early afternoon is hottest with mornings and evenings milder, while two others found it pleasantly moderate compared with central Kusatsu baths.
stated by 8 visitors · Jun 2023 – Aug 2026Day-use visits
Outsider access has flip-flopped since COVID and signage lags reality: reviews from 2023 through mid-2025 report non-residents barred (one calls access 'grey' with the COVID ban sign still up in Dec 2024; another in Jun 2025 says outsiders are banned due to tourist manners; one Aug 2025 review says outsiders may enter at night only), while a Jul 2026 reviewer confirms outside use is now allowed again but one old 'no outsiders due to COVID' sign remains posted.
stated by 6 visitors · Sep 2023 – Jul 2026Price
This is one of Kusatsu's free community baths — 3 distinct reviewers state it is free — but at least 5 reviewers stress leaving a small donation (sunshi) in the wooden box at the edge of the changing room to thank the district residents who maintain it.
stated by 6 visitors · Aug 2023 – Aug 2026Staffing
Completely unmanned, resident-maintained community bath: bathers themselves switch the lights on and off (3 distinct reviewers) and are expected to greet others and clean up after bathing (etiquette stressed by 3+ reviewers); the only staff contact is by phone to the district, which one reviewer found dismissive and unpleasant.
stated by 6 visitors · Aug 2023 – Aug 2026Day-use visits
Visitor access rules (as of 2025-2026 reviews): cleaning 9:00-11:30 and a residents-only window 15:00-21:00, so non-residents should bathe outside those windows — two reviewers report matching posted rules, and a third summarizes it as open to non-residents from 11:30 until evening; two more warn generally that there are hours when outsiders cannot enter, one noting the exterior sign lights are off at night even though it is open.
stated by 5 visitors · Apr 2025 – Aug 2026Towels, soap & lockers
No soap is provided (one reviewer); unusually for a Kusatsu communal bath there is one shower plus two taps/washing spots (two reviewers give these counts, one noting the shower is a relatively recent addition useful for cooling off); a Western-style toilet is available inside (two reviewers).
stated by 5 visitors · Dec 2023 – Jul 2026Timing
When to go
Quietest Sunday around 2:00; busiest Saturday around 23:00. Measured by Google over past visits, not a forecast.
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Quiet Busy
| Day | Hours |
|---|---|
| Monday | 11:30–15:00 |
| Tuesday | 11:30–15:00 |
| Wednesday | 11:30–15:00 |
| Thursday | 11:30–15:00 |
| Friday | 11:30–15:00 |
| Saturday | 11:30–15:00 |
| Sunday | 11:30–15:00 |
Practical
Plan your visit
📍 464-1340 Kusatsu, Agatsuma District, Gunma 377-1711
🚃 Gunma-Otsu station, 7.7 km
📞 +81279-88-0001
📋 Show at the counter: こぶしの湯（万代鉱源泉）
Nearby
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