A married couple named Kano and their neighbors, the Kanda family, live in the same apartment complex and have made it a tradition to get together once a month for drinks. One evening, while all four are enjoying some drinks, Mr. Kano brings up a TV show about husband-wife swapping. In a twist of fate, they decide to participate in the swap themselves. However, what starts out as innocent fun takes an unexpected turn... *Note that the contents may vary depending on the distribution method.