Chii-chan Kaihatsu Nikki / Chii's Development Diary

Meet Chisato Mashiro, an outwardly typical young girl who only thinks about boys and is dating her senpai.

Usually a quiet, obedient girl, she is going through her rebellious period, and often the target of her outbursts is her uncle, who is upset that the once cute little girl who always played with him has become such a foul-mouthed (although he has nothing against some of her parts, which have also grown along with her)

One day Chisato catches her uncle rummaging through her underwear drawer, and enraged by this, she unleashes a stream of verbal insults and threats, realizing that her uncle has crossed all boundaries. He, in turn, decides that he has had enough of this behavior, and decides to take matters into his own hands and take a more active role in raising his beloved Chi-chan. @Anitokyo