Anime XXX - Keraku no Ou 2

Ryouichi has no friends, is often beaten by bullies, and even his own parents have given up on him. When a new girl joins his class, his life takes a turn for the better. Ryouichi was a childhood buddy of Chihiro's. As a youngster, she didn't know that he had suffered brain damage as the result of an accident. She promises to do everything for him out of a deep sense of shame. Ryouichi takes advantage of the circumstance to ask for sex from her. Chihiro's conscience won't let her back out, so she accepts. As time goes on, Ryouichi discovers that he has a hidden weapon in the bedroom. Retribution has become his main goal after enduring years of bullying at the hands of his peers. A perverted adventure begins in which all of the ladies who rejected him are transformed into his sex slaves.