Fukushuu ~Ryoujoku no Yaiba~

Nakazawa Yuuichi has been bullied without reason since childhood. In order to change his circumstances, he transfers to another school. Unfortunately, he ends up being bullied again, this time by a bunch of girls. One day, a girl named Iida Yui comes to his rescue but consequently becomes a target herself. They support each other through emails and become close, but their happiness is short-lived. Yuuichi is restrained by his bullies and forced to watch as Yui is sexually assaulted before his eyes. He decides to take revenge.

[Translated and condensed from Getchu]