22-year-old Eikichi Onizuka: pervert, former gang member... and teacher?

Great Teacher Onizuka follows the incredible, though often ridiculous, antics of the titular teacher as he attempts to outwit and win over the cunning Class 3-4 that is determined to have him removed from the school. However, other obstacles present themselves throughout—including the frustrated, balding vice principal, Hiroshi Uchiyamada; old enemies from his biker days; and his own idiotic teaching methods. But Eikichi fights it all whilst trying to help his students, romance fellow teacher Azusa Fuyutsuki, and earn his self-proclaimed title.

Also contains the gaiden "GTO: Great Toroko Oppai♡" (Tomoko's Big Adventures).

GTO won the 22nd Kodansha Manga Award in the Shounen category in 1998. The series was published in English as GTO: Great Teacher Onizuka by Tokyopop from April 23, 2002, to August 9, 2005. Kodansha Comics USA republished the series digitally on February 1, 2022. It was also released in Polish by Waneko from June 2004 to June 2010. Several live-action adaptations of GTO were made. A 12-episode television drama was broadcast from July 7, 1998, to September 22, 1998. A revival of the drama series aired on April 1, 2024. It was followed by a live-action film released on December 18, 1999; the film became the 10th highest-grossing Japanese film of 2000. A second drama adaptation was broadcast from July 3, 2012, to September 11, 2012. A joint project between Japanese and Taiwanese productions called GTO in Taiwan aired first in Taiwan from March 22, 2014, to April 12, 2014, and later in Japan. Another GTO drama aired from July 8, 2014, to September 16, 2014.