Injuu Kyoushi
English name: Angel Of Darkness
Genres: Horror, Supernatural, Hentai
Type: OVA, Episodes: 4
Aired: Oct 21, 1994 to Nov 22, 1995
Studio: Horannabi
Source: Unknown
Rating: Rx - Hentai
Synopsis:
Atsuko and Sayaka think they have it made when they are both accepted into the same prestigious women`s academy. There, they will be free to explore the intense passion of their relationship, unbounded. 

But when the mystical bonds imprisoning a hideous ancient evil that feeds on the lust of nubile women are accidentally broken, the two young lovers soon learn they have more to fear than final exams.