The main character, Satoru Tsuzaki, has feelings for Chiho Mizumori, a young widow who lives in the same apartment complex. Due to his timid personality, Satoru is unable to express his feelings to her. He meets Kanae Ma. Kanae learns of her feelings for Chiho, and seeing Satoru's unwillingness to be proactive, Kanae decides to help her with her love life. In order to somehow gain her confidence, Kanae invites him to have sex with her, but...