Gedou Gakuen
English name: Nightmare Campus
Genres: Supernatural, Hentai
Type: OVA, Episodes: 5
Aired: Oct 21, 1994 to Jun 28, 1996
Studio: Phoenix Entertainment
Source: Unknown
Rating: Rx - Hentai
Synopsis:
During an archeological expedition to a forbidden Himalayan temple, 19-year-old Masao Sera stumbled upon a bloody, sacrificial rite designed to throw open the Gates of Hell. Meanwhile, a dark force has descend upon Masao's college. Fights, gang violence and rape are the order of the day. But now, some of the gangs have started to develop supernatural powers and unholy appetites. As demonic entities battle for control of the campus, the conflict threatens to grow into armageddon when Masao mysteriously returns with the King of the Underworld bound to his mortal soul. 

(Source: ANN)