Swapping gurui: Yamanote wafuku fujin-hen.

The Ohtani couple, Makiko and Shinji, are going through a rough patch in their marriage. Seeking excitement, they attend orgies with swap enthusiasts, and when they're alone, they have sex while watching swap videos. However, Makiko secretly feels disgusted by swapping, but Shinji, who is addicted to it, forces her to participate without giving her a choice. Seeking even more excitement, Shinji heads to a party hosted by the infamous "Jiyugaoka Lady"...