Kayo and Kuniko graduated from girls' school together and are as close as sisters. Kuniko's fiancé, Minakami, feels something that attracts him deeply towards Kayo. On the other hand, Kayo prays for the happiness of her best friend and marries a very ordinary man. However, at one point, this mediocre but increasingly ferocious husband died in an accident ... A triangular love story develops depicting a woman's heart that sways between love and morals.