My brother and his wife went abroad for urgent work. While I'm away, I'm supposed to take care of my niece, Mito, but they're strangely close to each other, and as if to show off, she shows off her defenseless side. One day, he encounters Mito masturbating in the living room and finds out that he is peeping on her. However, it was a show-off temptation from my little devil niece!