Tsugunai - 1

The main character lives with his sister Nana after their parents died as a result of an accident.
Once his sister, Nanu, was defiled by a group of rich men. The hero is arranged by a teacher at a school for girls, where the children of those who dishonored his sister are studying, and after, having picked up the moment, he invites them to the remote villa under the pretext of additional classes to carry out his revenge.
Tsugunai tells the story of Nana, schoolgirls which is subjected to violence from the group of wealthy men. Her brother, a teacher of a prestigious school, takes a group of students to a remote village to give them additional lessons, but this is not his real purpose, he took them there to brutally mock them, since these girls are the daughters of the guys who mocked them his sister. In this first chapter, the teacher mainly mocks Sayzu Ruriko.