Sugimoto, a younger colleague her husband has always looked after, returns from a branch office to work with him at headquarters. The couple frequently invites the single man over and looks after him. One day, Sugimoto can no longer contain his desire and makes a move on Yuko, and they have sex. Already conscious of her nearly nonexistent sex life after her sister-in-law pointed it out, Yuko knows the affair is wrong but finds herself drawn to everything Sugimoto offers that her husband does not.