Married for four years, Nanami and Koji's marriage life is gradually falling into a deadlock. Koji is getting busier with work, often coming home late, and the two rarely talk to each other... In contrast, a newly moved couple, Hibiki and Abe, always show affection towards each other, to the point where Nanami can clearly hear Hibiki's moans during their intimate moments. The love between Hibiki and Abe makes Nanami feel extremely jealous. After the two women get acquainted, Nanami shares her story with Hibiki. Upon hearing it, Hibiki immediately invites Nanami and her seventh husband to their house. Here, she proposes a spouse swap between the two families. This will only happen on weekends, with no contact or private meetings on other days. Wanting to change her current life, Nanami agrees. The next day, she goes to Abe's house and becomes his wife. Abe, a gentle and caring person, easily brings a sense of safety and joy to Nanami. Days go by without any trouble. The following week, Nanami continues to be Abe's wife. But this time, Abe cannot resist Nanami's beauty. When they share a bed, he 'invades' her body. Nanami weakly resists as her body also welcomes the pleasure she has long forgotten. And the next week, Nanami still continues to visit, but this time she is more proactive, enjoying the pleasure of sexual intercourse with Abe.