JUL-806 My beautiful sister, who I would never mess with, and I are stepchildren who are not related by blood... - On a summer day, the two lose the bond of being siblings and indulge in a forbidden affair. - Yuka Aota

At the end of the hot summer, I returned home to celebrate the 17th anniversary of my mother's death. - Every year, no matter how busy I was, I always found a reason to go home because of my older sister, Yuuka. - My sister is the woman I admire who has taken care of me in my mother's place ever since I lost my mother when I was a child. - Although we are both married now, I have always had feelings for my sister that are more like that of a brother and sister. - Then, that night, at the end of the memorial service, my father called us and confessed to us that the two of us were not really siblings.