Eun-mi and her husband have been married for 5 years, but they rarley have sex. Eun-mi goes through her SNS one late night and finds a post about 'invitation girls'. After thinking about it for a few days, she signs up for it and gets invited by Hyun-ji and her husband for a new and stimulating experience. Eun-mi shared her experience with her husband and 'swaps' with Hyun-ji and her husband....

A man prepares a surprise for his wife on their 5-year-anniversary. One day, a couple, a man in the middle of a divorce and his mistress, come to visit. An entangled romantic web ensues.

Jun-yeong and Sook-hyang, who have been married for 5 years, are a couple who seem to be unhappy. Because of Sook-hyang's insensitivity, their marriage weakens. One day, Sook-hyang met her first love, Yeong-min and his wife, Mi-seon. Sook-hyang receives a shocking invitation to have sex together...