JUL-920 My beloved stepsister, who raised me single-handedly, was stolen by her shitty friend… Naohito Jinja

Sister Nao and I are not real siblings. When she was a student, her father's remarried partner's child was Nao's older sister. After that, after her parents died in an accident, my older sister, Nao, became my parent. There was loneliness in our life together, but I also felt happy because I was in love with Nao. One day, Yuzuru, her best friend, was secretly talking to her sister Nao, and when she approached him while remembering her jealousy, he was successfully dodged. And after a certain point, Nao's sister often comes home late...