The fourth of nine public bathhouses in Shibu Onsen, Yamanouchi Town, Nagano Prefecture. This bath was named when hot spring water was successfully piped from Jigokudani (Hell Valley). The water quality is sodium-calcium sulfate-chloride hot spring (weakly alkaline, hypotonic, high temperature) with a source temperature of 86.5°C, the highest among the nine baths. The bathing temperature is adjusted to approximately 50°C. It is said to be effective for chronic gout. Shibu Onsen was discovered about 1,300 years ago by the monk Gyoki, and during the Sengoku period it was known as one of Takeda Shingen's hidden hot springs. It is said that wounded soldiers recuperated here during the Battle of Kawanakajima. This is the only weakly alkaline spring among the nine baths, offering a different bathing sensation compared to the others.