Five couples gather for a tense swapping party, each carrying private frustrations and desires. Hostess Tada Yuka attends the event arranged by her impotent husband. Isshiki Momoko brings her adult son and pretends he is her husband in an adult role-play. Tomoda Maki hopes to hold on to her younger lover, Hiraoka Rieko is trapped in a sexless marriage, and Mizuno Yuka lives with a habitually unfaithful husband. As their motives collide, the partner-swapping feast begins.