Hotel SPAX Kusatsu: 24-Hour Hot-Spring Baths, Pool Days and the Outdoor-Bath Rotation

Hotel SPAX is a practical choice if you want late-night or early-morning access to Kusatsu’s Bandai-kō spring and are happy to use shared facilities. The pool and outdoor bath need a little more planning: a pool on the property does not mean it is open on every weekday, and only one side of the men’s and women’s bathing areas has the outdoor bath at a time.

Both flow figures describe the source system, not this hotel or an individual tub; neither temperature is a bath-temperature reading. A November 18–19, 2026 rate snapshot for two adults showed availability from about NT$4,946. That Wednesday falls outside the regular Friday-to-Sunday pool schedule, so the rate does not establish pool access.

The indoor baths are the reliable part of the schedule

The hotel describes its public baths as 100% natural hot spring water from Bandai-kō, supplied on a free-flow basis. The indoor baths are open 24 hours, except for cleaning from 6:00 to 6:30 am and 10:00 am to noon. Men’s and women’s indoor baths are separate, and both have a sauna that runs from 3 pm to 10 pm.

There is one outdoor bath, shared by a daily gender rotation. That means a one-night stay does not guarantee that both partners can use it; one may have access on arrival day while the other has only the indoor bath. Ask which side has the outdoor bath on your dates if that is important.

Check pool operating days before booking for the children

The indoor heated pool is free for overnight guests, but its standard schedule is Friday through Sunday year-round, plus Golden Week, summer, spring and winter holidays, and the year-end/New Year period. The usual opening time is 10 am to 7 pm. Guests need swimwear and a swimming cap; caps are available to rent or buy.

For a weekday outside those holiday periods, confirm the pool is open before making it the reason for choosing the hotel. The hot-spring baths have a much broader daily schedule than the pool.

Bring swimwear and a swim cap; caps can be rented or purchased. Overnight guests use the pool free when it is open. The hotel does not offer a private bath, and its current pages do not state a single tattoo policy, so ask directly if either point affects your booking.

A hillside base near Sainokawara

Hotel SPAX sits on the Sainokawara side of town: Sainokawara Park is about five minutes away on foot, while Yubatake is around ten minutes away. The route back to the hotel is uphill. A free pickup from Kusatsu Onsen Bus Terminal is available from 8:30 am to 5 pm; call after you arrive, as the hotel does not offer this service after 5 pm.

Guest rooms range from compact twins to larger Japanese-Western rooms. The room page lists ordinary baths and showers, not in-room Bandai-kō spring water, so choose SPAX for the shared facilities rather than expecting a private onsen tub. For another property close to the same park, see the Sainokawara open-air bath guide. The Kusatsu three-bath guide helps place SPAX in the wider bathing area.

Room size changes the value noticeably: a renovated twin is about 23 m², while the larger Luxury Twin categories are around 46 m²; Japanese-Western rooms are also available for groups. The hotel’s pages and booking listings do not agree on one checkout time. Standard rooms are often shown with 10 am checkout, while newer facility information lists 11 am for some categories and 10 am for Japanese-Western B and Japanese rooms. Check the room plan, especially because the public baths close for cleaning from 10 am to noon.

The on-site restaurant serves Japanese kaiseki, with dinner from 6 pm (last entry 7:30 pm) and breakfast from 7:30 am (last entry 9 am). Breakfast-only and two-meal plans are available. The hotel says it cannot accommodate allergy-specific meals or menu changes. A ¥150 bathing tax per adult is collected separately.

If travelling by car, the hotel lists 30 free parking spaces; guest feedback notes that spaces near the entrance are limited, so a larger lot may be used. The terminal pickup is free from 8:30 am to 5 pm without advance booking, but you need to call after arriving. The hotel sits uphill from the park and town route, worth weighing in winter or with heavy luggage.

Sources

- [Hotel SPAX: hot springs and sauna](https://www.hotel-spax.com/hot_spring/) - [Hotel SPAX: pool and facilities](https://www.hotel-spax.com/facility) - [Hotel SPAX: guest rooms](https://www.hotel-spax.com/room) - [Hotel SPAX: access](https://www.hotel-spax.com/access) - Images: [Hotel SPAX facility image](https://www.hotel-spax.com/), [Kusatsu town photo](https://www.trip.com/) - Image: [Sainokawara Park, Wikimedia Commons](https://commons.wikimedia.org/wiki/File:251129_Sainokawara_Park_07.jpg)

Checked: September 27, 2026

Tags: Kusatsu Onsen, Hotel SPAX, Bandai-kō spring, swimming pool, sauna, Sainokawara