Yamamizuki

Yamamizuki is a hotel spa built around the hot-spring tradition of Kurokawa Onsen, a cluster of ryokan in the mountains of Kumamoto known for outdoor bathing. The property's baths draw on the area's thermal water, offered as outdoor pools rather than an indoor spa circuit.

Bathing here follows standard onsen custom: the baths are clothing-optional, meaning guests bathe nude as is typical at Japanese hot springs, rather than in swimwear. There is no day-pass option listed, and access is limited to hotel guests staying at the property, so this isn't a stop for travelers passing through Kurokawa Onsen looking for a single soak.

Booking happens by phone rather than through a walk-in or online day-use system. The reservation line, 0967-44-0336, takes calls from 11:00 to 20:00. Beyond that, the official website can be checked for seasonal details, room types, and anything related to rates or stay packages, since specific hours for bath use and pricing aren't published.

For anyone already planning a stay in Kurokawa Onsen, Yamamizuki fits the pattern of the town's ryokan-centered hot-spring culture, where the emphasis is on an overnight experience tied to the baths rather than a quick visit.