Yuyama Onsen Motoyu

Motoyu is a public bathhouse in Yuyama, Mizukami Village, Kuma District, in the southeastern corner of Kumamoto Prefecture. It sits in a mountain valley upstream of the Ichifusa Dam along the Yuyama River, at the foot of the sacred Mount Ichifusa (1,722 m) in the Kyushu Central Mountains. The spring is said to have flowed here since ancient times, and the bathhouse has long served as the communal bath of the Yuyama hot spring settlement. It is a village-run facility, with enquiries handled by the Mizukami Village Council of Social Welfare.

The water is an alkaline simple sulfur spring, measured at pH 9.46 in the village survey of fiscal 2023. Its trademark is a notably slippery, silky texture, and the bath is known locally as a bijin-no-yu, or beauty bath, said to leave the skin smooth. The water is supplied in natural free-flowing style, and the listed benefits include neuralgia, lower back pain, cuts, skin complaints and chronic gynaecological conditions.

Both the men's and women's sides have an indoor bath and an open-air bath, built as rock pools using local natural stone. There is no sauna and no private family bath, leaving the water itself as the sole attraction. Admission is 410 yen for adults and 210 yen for children. The bath opens from 10:00 to 20:00 and closes on the third Wednesday of each month. Parking for 30 cars is provided, and a rest room on the upper floor has a coin-operated massage machine (100 yen).