``Welcome to the couple swapping party, I'm Tada, the host.'' The atmosphere was tense among the five couples gathered at the venue...each couple had their own worries and desires. Wife Arika Tada attends a party prepared by her impotent husband. Momoko Isshiki is a married woman who pretends to be her husband and takes her son with her. Maki Tomoda is a married woman who wants to keep her young lover. Rieko Hiraoka has no sex with her husband because of her seriousness. Yuka Mizuno has a husband who has a habit of cheating. Amidst the confusion of various thoughts, the swapping party begins...