A chance reunion with old college friends at a hot spring resort turns into a shocking revelation for a newlywed husband when he discovers that his wife shares a complicated and intimate history with each of the men in their circle. The OVA follows Hiroshi and his wife Ayaka as they encounter three male friends from their university days, including the enigmatic Endou. What begins as a nostalgic getaway quickly escalates as the husband witnesses his wife's uninhibited past resurface in real time, forcing him to confront just how liberated she truly is.

The main characters include Ayaka, a newlywed wife whose past relationships within the college circle gradually come to light; her husband, who struggles to reconcile the woman he married with the stories being revealed; and the three old friends, each of whom had a distinct and personal connection with Ayaka during their school years. The narrative unfolds entirely within the setting of a traditional Japanese onsen, where the relaxed atmosphere and private bathing areas create a backdrop for secrets to slip out.

As the evening progresses, each friend takes a turn accompanying Ayaka away from the group, returning with increasingly disheveled appearances that leave little to the imagination. The husband watches these encounters unfold, his expression shifting from confusion to a strange sense of humor at the absurdity of his situation. The story builds toward a final group scene within the hot spring itself, where all boundaries dissolve entirely and Ayaka fully embraces her nature without pretense. Throughout the OVA, the narrative focuses on the husband's journey from shock to acceptance, questioning how well any person can truly know their partner and just how far their lifestyle might take them.