Tochiomata Onsen Jizaikan is a hot spring inn with approximately 400 years of history and a member of the Japan Secret Hot Springs Association, located in Uonuma City, Niigata Prefecture. Known as a radium hot spring (radon hot spring), it boasts Japan's 2nd highest radium (radon) content. It's famous as a 'fertility bath,' said to enhance the function of reproductive organs including ovaries and testicles.

The hot spring is a simple radium spring with pH 8.6 weakly alkaline water that's colorless and transparent. The source temperature is approximately 35°C, which is relatively low, and the characteristic 'petit tōji' (short-term therapeutic bathing) style involves soaking for 1-2 hours. Long-duration bathing is said to relax the body and promote cell repair. While boosting metabolism, it has sedative, analgesic, and hypnotic effects, and is said to be effective for urinary tract inflammation, gout, diabetes, and mild atopic dermatitis.

Jizaikan is a petit tōji inn popular with women, where you can enjoy leisurely hot spring therapy in a quiet environment. The inn values the therapeutic bathing culture, and extended stays are recommended. Meals feature body-friendly dishes using local ingredients.

Tochiomata Onsen has other inns besides Jizaikan, such as Hōgandō, all sourcing radium hot springs. Accommodation rates are approximately 13,000-20,000 yen per person per night with two meals (varies by inn). Day-use bathing is available at some inns (confirmation required).

Access is by car from JR Joetsu Line Koide Station (about 30 minutes) or by bus (about 40 minutes). By car, it's about 25 minutes from Koide IC on the Kanetsu Expressway. Free parking is available. It's a precious hot spring inn where you can experience radium hot spring therapeutic bathing culture in a quiet mountain setting.