Houkago: Nureta Seifuku
English name: After Class Lesson
Genres: Hentai
Type: OVA, Episodes: 3
Aired: Jan 25, 2005 to Sep 25, 2005
Studio: T-Rex
Source: Visual novel
Rating: Rx - Hentai
Synopsis:
Shibui Ryuji is a teacher of a girl school whose students are born in well-off families. All students hate him because of his figure and perverted nature. However, he happens to know the weakness of Tenkawa Ayumi, so he raped her. Tasting blood, he begins to rape his students, one after another taking advantages of their weakness.

(Source: AnimeNfo)