A couple has nowhere to go after the husband's business fails. The wife, Mai, decides to contact Aya, an upper class student from her college days. Although Aya is married, she loves Mai more than her husband. Unable to refuse Mai's long-awaited request, Aya persuades her husband to let them live together for the time being. One day, Mai says that sex with her husband has recently lost its freshness, and to solve her problem, Aya suggests swapping.