Miho is a housewife in her seventh year of marriage, living with her husband, a businessman. One evening, her husband comes home with a friend named Yamashita. Yamashita is a mutual friend of the couple from their student days, and Miho knows him well. "It's been a while, Yamashita. Have you been busy lately?" Miho asks with a smile as she takes care of the evening drink. "By the way, I've started working out at the gym recently." "Look, look at these muscles." "Miho..."