At the end of the hot summer, I was returning home for my mother's 17th anniversary. Every year, no matter how busy she was, she tried to go home with a reason because of her sister Yuka. Her sister has been a longing woman who has taken care of me for her mother ever since she lost her mother as a child. Both of them are married now, but I have always had more feelings for her sister than siblings. Then, that night, we were called by my father at the end of the litigation and confessed that they were not real siblings ...