Great Teacher Onizuka (グレート・ティーチャー・オニヅカ Gurēto Tīchā Onizuka), officially abbreviated as GTO, is a Japanese shōnen manga written and illustrated by Tohru Fujisawa. It was originally serialized in Weekly Shōnen Magazine from May 1997 to April 2002. The story focuses on 22-year-old ex-bōsōzoku member Eikichi Onizuka, who becomes a teacher at a private middle school, Holy Forest Academy, in Tokyo, Japan. It won the 1998 Kodansha Manga Award for shōnen and is a continuation of Tohru Fujisawa's other manga series Shonan Junai Gumi (lit. "Shōnan True Love Group") and Bad Company, both of which focus on the life of Onizuka before he becomes a teacher in Great Teacher Onizuka. Wikipedia
Ayano Katsuragi: Are you suggesting schoolgirl prostitution?
Eikichi Onizuka: Not suggesting, insisting!