Hasunuma Onsen in Tokyo: Three Spring Baths and a Free-Flowing Cold Pool
All three pools at Tokyo's Hasunuma Onsen use natural spring water, including a free-flowing cold pool. Adult entry is ¥600; sauna costs extra.
Hasunuma Onsen is a good first Tokyo sento for anyone who wants natural spring water without committing to a large spa. Its three pools all use the source, and the cold pool is the unusual one: it is a free-flowing natural cold mineral spring. The water is described as pale yellow-brown, not the familiar dark Kuroyu often associated with other parts of Ota City.
What ¥600 gets you
| Entry | Price |
|---|---|
| Adult bath | ¥600 |
| Middle-school student | ¥500 |
| Elementary-school child | ¥200 |
| Preschool child | ¥100 |
| Sauna, with bath and face towels | +¥300 |
| Towel set for bath-only visitors | ¥200 |
Shampoo and body wash are available. The sauna ticket includes a bath towel and a face towel, so adult admission plus sauna comes to ¥900. If you only want the baths, you do not need to pay extra for towels unless you arrive without your own.
The water is a sodium-chloride and bicarbonate cold mineral spring. Hasunuma’s official description calls it pale yellow-brown; the hot main bath is heated, while the spring-fed cold pool is free-flowing. A third, gentler carbonated spring bath rounds out the small bathing area. This is not a resort with a view or a lounge: the appeal is the water itself and the polished, Taisho-romantic interior.
A sauna visit with a milder cold plunge
The sauna is a modest add-on rather than a large, multi-room sauna complex. What makes it interesting is the spring-water cold bath afterwards. It is much gentler than the very cold plunge pools some sauna enthusiasts seek, so it suits a slower hot-and-cool cycle better than a hard temperature shock.
Hasunuma Onsen explicitly allows guests with tattoos, provided they follow the bathhouse rules and do not disturb other guests. Families can bring babies; children aged six and under may bathe with a parent of another gender, while children seven and older use the bath matching their gender. There is no diaper-disposal service, so take used diapers with you.
The closest station is Hasunuma, not Kamata
Tokyu Ikegami Line’s Hasunuma Station is about a two-minute walk away. Kamata Station is around ten minutes on foot, which may be convenient if you are already on the JR Keihin-Tohoku Line, but Hasunuma is the simpler arrival point. The bathhouse opens 3 p.m.–midnight and closes Tuesdays.
There is one dedicated space outside and a partner coin car park. For the partner lot, collect the parking certificate and show it at the counter to receive the current service ticket; check the facility’s access page for the terms. If you are comparing local spring-water sento, the Otomeyu–Tsurunoyu comparison shows two different black-spring setups elsewhere in Tokyo.
Sources
- [Hasunuma Onsen: spring water and the three baths](https://www.hasunuma-onsen.com/onsen/) - [Hasunuma Onsen: current admission fees, hours and access](https://www.hasunuma-onsen.com/price/) - [Hasunuma Onsen: facility information and notices](https://www.hasunuma-onsen.com/) - [Hasunuma Onsen: frequently asked questions and visitor rules](https://www.hasunuma-onsen.com/faq/) - Images: facility images from Hasunuma Onsen’s official website. Checked: 2026-09-27Tags: Hasunuma Onsen, Tokyo natural spring, Nishi-Kamata sento, Tokyo sauna, spring-water cold bath
