Absolutely forbidden to touch her busty female friend, who tempts him into a week-long affair of unfaithful sex while his live-in girlfriend is away on a family trip for about a week. However, he takes the opportunity to get close to her best friend, Minami, who attended a drinking party she opened before her departure and took advantage of her being drunk and asleep. Then, after his girlfriend leaves for her trip, Minami comes over again, and for the week until she returns, he indulges in a decadent live-in life filled with daily debauchery and forbidden internal affairs.