We were in charge of the design, naming, and VI for a private sauna attached to an accommodation facility built to make use of an abandoned school, the former Kagura Elementary School, in Tamba City, Hyogo Prefecture. Based on the structure of a barrel sauna, we installed a long and narrow window with a stepped ceiling to allow light to enter in the morning. As a result, the round roof with the step became a new icon. This sauna is located in Aogaki, Tamba City, Hyogo Prefecture, which is filled with the headwaters of the Kako River. The sauna’s water bath uses this high-quality natural water and the thinned wood cut down from the mountains by the company that operates it, MOKUEI Co. Based on this concept, we named the sauna “Yoki Sauna” with the symbol mark of four trees circulating.