At the beginning of summer, the sound of cicadas could be heard, and my sister Ayame and I returned to our parents' home for the 17th anniversary of our mother's death. The reason we returned to our parents' home every year was because of my sister Ayame. She was a kind and adored sister who had taken care of me in place of our mother, who had passed away early. Although we are both married, I still have special feelings for my sister that go beyond that of family. Then, at night after the memorial service, my father called me with a serious look on his face and told me that we weren't really siblings...