Mesu Kyoushi 3: Inetsu no Gakusha Touko-hen

When Tatsuya woke up, he had lost his memories. He couldn't even remember his own name, but with the help of his homeroom teacher, Touko, and other teachers, he is able to live his school life without any difficulties. However, when Tatsuya investigates how he lost his memory, he discovers Touko's true intentions. This triggers Tatsuya to give in to his deep-seated lust, and he rapes her. In order to relive the intense arousal and pleasure he felt there, he begins to fuck the other female teachers, Leena and Yurika, as well…

(Source: Paradigm Novels, translated)