Like most couples in the world, the marriage life of Qiong (played by Kim Sun-young) and Heng (played by Kim Young-ho) gradually became dull. Qiong's busy work made her have no time to take care of her husband's feelings and needs. Over time, there was inevitably a estrangement between the two.In order to resolve the crisis in the marriage, the couple decided to go out for a vacation together. Unexpectedly, on the night of the vacation, Heng told Qiong that he had disappointed her and could no longer have an erection.At this point, the relationship between the couple took a sharp turn and even reached the verge of breaking down.At this critical moment, Heng received a mysterious email from Butterfly Club, and the sender of the email was actually the organizer of the wife swap game.At first, the couple decided to ignore this ridiculous game, but they were shaken as their marriage became worse and worse.