Shinji is a little dissatisfied when his wife's sister, Ena, is supposed to be on a hot spring trip alone with his wife. However, when her wife rushes out of her inn due to a sudden job and is alone with her, she receives a certain advice from her... that triggers a closer relationship between Ena and her. However, she could not resist her invitation approaching devotedly, and put her body on top of it. Since he was sexless, Shinji persuades him to only do it once. However, Ena sneaks into the futon without worrying about that...
