Natsuko is a devoted housewife who deeply loves her husband, Hiro. However, lately, Hiro has been feeling bored, causing a slight distance in their relationship. One day, Hiro receives a suggestion from a friend—to let Natsuko have sex with another man in hopes of reigniting his own passion. With hesitation but a desire to save her marriage, Natsuko agrees for the sake of her husband. Finally, Hiro calls upon you, his neighbor, to try having sex to Natsuko.