Living together with Yoshio, her husband's stepson from his remarriage, is the stepmother, Kyoka. With her husband away on a business assignment, days pass with him absent. Confused by her growing romantic feelings for Yoshio, Kyoka struggles internally—yet Yoshio has long harbored feelings for her as well. Tormented by jealousy, he suffers alone, imagining Kyoka writhing in anguish as she's taken forcefully by her friends. Eventually, Yoshio's emotions reach her, and their relationship takes a new, forbidden turn.