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