Gorillaman
Genres: Comedy
Type: OVA, Episodes: 2
Aired: Jun 25, 1992 to Dec 24, 1993
Studio: J.C.Staff
Source: Manga
Rating: R - 17+ (violence & profanity)
Synopsis:
A school comedy about a mute transfer student, Tadashi  Iketo, who is constant­ly shuffled from school to school for his  "violent nature," though he really is a mild-mannered boy constantly taunt­ed into fights over his simian appearance. 

Based on a 1989 manga in  Young Magazine by Harold Sakuishi. 

(Source: The Anime Encyclopedia)