Mizuki is not a real sibling. When I was a student, my parents remarried and we met each other. Several years have passed since then, and after her parents died in an accident, they lived together while supporting each other. As we continued to live alone, I began to fall in love with Mizuki. The dream she envisioned with Mizuki as it is is stolen by her best friend Kyohei. Kyohei, who likes Mizuki, is jealous of her relationship with us, and suddenly approaches Mizuki when I'm not around.
