Nishikamata, Ota, Tokyo
Hasunuma Onsen
A neighborhood-priced natural spring bath with a source-fed cold pool and a separately priced sauna. It is a sento, not a full-service spa, and the main bath's fixed temperature is not published.
Facility photos
Check before bathing
- Opening hours
- 15:00–24:00; closed Tuesdays. Adults ¥600, junior-high students ¥500 with student ID, elementary-school children ¥200 and younger children ¥100. Sauna is ¥300 extra and includes a bath towel and face towel; a towel set costs ¥200.
- Tattoo policy
- The operator explicitly allows guests with tattoos, provided they do not bother other guests or staff.
Spring & water temperature
- Spring-source temperature
- About 19.8°C in a transcription of the 2024-09-18 analysis; the operator's current text page does not publish an exact figure.
- Bathing temperature
- No fixed temperatures are published. The operator identifies the main pool as heated, the carbonated pool as milder and the cold bath as source-flowing.
- Spring source
- Hasunuma Onsen.
- Spring classification
- Sodium chloride-bicarbonate cold mineral spring; low-salinity and weakly alkaline.
- pH
- About 7.7 in the same dated field transcription; not published on the current operator text page.
- Flow rate
- 44 L/min in the same dated field transcription; not published on the current operator text page.
- Water handling
- The operator confirms that all three pools use natural spring water. The cold bath is source-flowing, while the main bath is heated. A 2024 analysis transcription also lists no added water, circulation or chlorine treatment for the heated bath, but this is secondary field evidence rather than a current text-page specification.
Older website listings of ¥550 and midnight-plus hours are out of date. Check the facility's news for temporary closures.
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.
