At the end of a hot summer, I was able to return to my hometown to celebrate my mother's 17th birthday. Every year, no matter how busy I am, I try to go home for the sake of my sister, Yuka. My sister is a devoted woman who has taken care of me ever since I lost my mother when I was young. Currently, both of us are married, but I always feel closer to my sister than to my brother and older sister. Later that night, my father called us in after the dispute and confessed that they were not our biological siblings...