Weekend. In a Tokyo apartment, hardworking salaryman Shintaro is hurriedly cleaning the room in preparation for the arrival of his mother-in-law, who is about to visit from his wife's hometown to check on her daughter and son-in-law. Hearing the doorbell, Shintaro quickly opens the door and welcomes his mother-in-law, Chiaki Shinomiya. Unconsciously holding his breath and feeling his heart race, he is struck by her voluptuous figure.