When college student Tsuyoshi comes back to his apartment after a trip to the convenience store, he is taken aback by Yui Kooriyama standing at his door. His mother had sent her to keep an eye on him, and Yui barges into his private space. Even though Yui is already married, the ordinary visit quickly turns when they become intoxicated and spend a night together. When other married women invite him for more drinks, Tsuyoshi ends up sharing various intimate moments with them.
