Haruka Miyama is a charming and sweet married woman who sees Hiro-kun, her best friend’s son, as a member of her family. However, things get complicated when Hiro confesses his love and seduces Haruka while her husband is out of town on a business trip. Despite knowing that what they are doing is wrong and seeing Hiro as a potential son-in-law, she tries to reject his feelings without hurting him, but ends up giving in to pleasure.