At the end of the hot summer, I returned to my hometown for the 17th anniversary of my mother's death. Every year, no matter how busy I was, I would find an excuse to go back because of my older sister, Yuuka. Ever since I lost my mother as a child, my older sister has been a mother figure to me, a woman I admire. Although they are both married now, I have always had feelings for my sister that go beyond that of siblings. Then, that night, my father called us after the memorial service and confessed to us that we weren't really siblings...