Rio grew up with her mother, who had to work hard to raise her alone, giving her the best of everything. That's why when her mother introduced her to Uncle Shinzo and saw her mother happy with that man, Rio also felt happy for her mother. However, she still felt that this man was a bit strange. And as Rio suspected, when her mother was not at home, he sexually assaulted her! Not wanting her mother to be sad knowing that the man she loved sexually assaulted her own daughter, Rio tried to endure it. The stepfather also realized this and took advantage of the situation, forcing her to obey and have sex with him whenever he wanted.