When college student Tsuyoshi returns to his apartment from a convenience store, he is surprised to see Yui Kooriyama at his doorstep. Sent by his mother to check up on him, Yui forces herself inside his personal living space. Despite Yui already being married, the seemingly normal visit takes a sudden turn when they get drunk and spend a night together. As he is invited for more drinks by other married women, Tsuyoshi finds himself sharing all kinds of intimate moments with them.