Naou sister and I are not real siblings. During our student days, my father remarried, and Naou sister was the stepchild he brought along. After that, when both of our parents died in an accident, Naou sister, who is older than me, became my guardian. Living together, we felt loneliness, but since I had feelings for Naou sister, I also felt happiness. One day, my close friend Yuizuru was secretly talking with Naou sister, and as I approached feeling jealous, I was skillfully evaded. Since then, Naou sister has been coming home late more often…
