The hot spring at Noboribetsu in Hokkaido — Japan's northernmost major island, where the Noboribetsu Onsen complex sits at the edge of the volcanic "Hell Valley" with its boiling pools and sulphur vents — is Senpan's subject in this undated nude composition. The onsen setting provides the natural context for the female nudity that was Senpan's most characteristic figure subject, the communal bath a space where nudity was entirely normative and where the quality of physical ease and social relaxation that he found most compositionally compelling was genuinely present.