Hoshi Onsen, Minakami, Gunma
Hoshi Onsen Chojukan (Day Use)
Chojukan is for visitors who want the historic Hoshi-no-Yu building and natural spring water rising through the pool floor, not a long or flexible visit. The short reception window and mixed-bath rules need to work for your group.
Check before bathing
- Opening hours
- Ordinary day-use admission is ¥1,500 for adults and ¥500 for children aged three through elementary school. Reception is 11:00–13:30, and visitors must leave by 14:00. The inn is usually closed Wednesdays, has other irregular closures and does not accept day visitors over the New Year period. September 2026 notices listed closures on the 15th–16th and 24th, a ¥2,000 adult rate from the 19th–23rd, and opening on the 23rd; those dated exceptions have passed, so check the current schedule.
- Tattoo policy
- The current official pages checked do not state a tattoo policy. Contact the inn before visiting.
Spring & water temperature
- Spring-source temperature
- About 40°C overall according to the current overview; the inn lists 43°C for Hoshi-no-Yu. Chojuno-Yu's individual figure is not published.
- Bathing temperature
- Not published as fixed values. Hoshi-no-Yu has four pools with different temperatures; Chojuno-Yu's fixed temperature is not listed.
- Spring source
- The inn's own springs, emerging through the floor of Hoshi-no-Yu and Chojuno-Yu; individual formal source names are not published in current text
- Spring classification
- Hoshi-no-Yu: calcium-sodium sulfate spring. A separate current classification for Chojuno-Yu was not confirmed.
- pH
- Not published
- Flow rate
- Not published; the inn says Chojuno-Yu has its highest source inflow relative to pool volume but gives no L/min figure
- Water handling
- Both day-use baths receive spring water directly through the rock floor. The inn describes Hoshi-no-Yu as 100% natural spring water emerging among the stones; Chojuno-Yu also has floor-level emergence and the highest spring inflow relative to its pool volume in the inn. Full treatment details are not inferred across both pools.
Bathing indications
The inn lists general bathing indications for Hoshi-no-Yu, including digestive complaints, burns and arteriosclerosis. This is not a treatment guarantee.
Hoshi-no-Yu is mixed bathing; bathing garments and towel wrapping are not allowed. Chojuno-Yu is women-only. Standard hours are 11:00–13:30, departure by 14:00; Wednesday is the usual closure. Tattoo rules are unconfirmed.
How to read a bath profile
Spring-source temperature and actual bathing temperature are kept separate. Each score is shown independently for comparison rather than collapsed into one overall score.
