Tsugunai

After the protagonist’s and his sister Nana Kaisaki‘s parents die, the two live entirely on their own. Despite this, everything is going great – until one fateful day, Nana is insulted, kidnapped and raped by rich snobs. Her brother then vows revenge and starts working as a teacher at a private school attended by the daughters of said snobs. His plan: to gain their trust to eventually exploit it in private tutoring sessions and do to them what their fathers did to his beloved Nana. And lo and behold, the plan goes better than ever expected! A little stubborn at first, even the arrogant Ruriko Saijou slowly begins to trust him. A mistake she will later regret.

ツグナヒ, Tsugunai, 츠구나히