Hoshi Onsen Chojukan

Hoshi Onsen Chojukan is a secluded hot spring inn (hitou no ikkenyado) in Joshin’etsu Kogen National Park at the foot of Mikuni Pass. Founded in 1875 (Meiji 8), it preserves the atmosphere of the Meiji era with nationally registered tangible cultural property buildings including the main building and annex, totaling four buildings. Its hallmark is the Rococo-inspired grand bath “Hoshi no Yu,” a beautiful structure that was once featured in a JR advertising poster. There are three bath areas. Hoshi no Yu is mixed bathing and features rare naturally springing onsen water that bubbles up from between the river stones laid on the bottom, delivering its beneficial components directly. Tamaki no Yu is entirely hinoki wood and very open; it uses a time-slot gender rotation system and includes an outdoor bath—night bathing under the stars is recommended. There is also the women-only Chojuno Yu. This hot spring received perfect scores from the Japan Natural Hot Spring Inspection Organization across six criteria, including source/spring quality and utilization source details, as well as bathtub usage factors such as water addition, in/outflow method, and fresh-water injection rate. Overall, it’s an inn with truly wonderful buildings and hot springs.