The story of a certain boy. A few years ago, my mother and father divorced because of my father's affair. Then I had a new mother. Is it a so-called mother-in-law? So I have two mothers. Izumi Terasaki, my mother who gave birth to me and raised me up to this point. Kaori Otonashi, a stepmother who treats me kindly even though her blood is not connected. Aside from my father Tatsuo, I can live under one roof with two important people. I simply thought that a happy life was waiting for me ...