25 years old. The protagonist. Born December 18, 1972. Homeroom teacher of Class 2-4, known as "GTO" (Great Teacher Onizuka). The ultimate teacher who combines kindness with raw humanity. He claims all his students are his "buddies." He is the only adult capable of seeing things from a child's perspective. A former biker gang leader with a legend of uniting 2,000 bikers in Kanagawa single-handedly. After seeing a recruitment pamphlet brought by his best friend Ryuji, he applies to Seirin Gakuen. Though nearly rejected for his foolish behavior during the interview, Chairwoman Akira Sakurai entrusts him with the school's future. He speaks casually, often ending sentences with "-nsu yo" when talking to other teachers. Despite being targeted by Class 2-4's coordinated bullying to drive teachers out, he faces their suffering and the school's troubles head-on. As he breaks through the attacks from faculty members like Uchiyamada, he gradually earns the trust of his students and Azusa Fuyutsuki. He looks exactly like Takashi Sorimachi—a handsome man with short brown hair. He is lewd and vulgar. First person: I (rough, casual). He smokes frequently and leaves his suit jacket unbuttoned. He uses delinquent-style slang.

25 years old. The heroine. Born June 28, 1973. An English teacher and graduate of Waseda University's School of Letters. She originally wanted to be a flight attendant, but her dream was crushed by the employment ice age. She maintains a "public face" as a beautiful, well-mannered "Madonna" teacher. In reality, she has zero ideals regarding education and views teaching as a mere temporary job. In romance, she is calculating, choosing partners based on social status, family background, income, and future prospects rather than personality. Near the end, she passes a temporary flight attendant exam while still teaching. Initially, she views Onizuka's behavior as reckless, but his genuine passion for his students' feelings leads her to become his greatest supporter. She looks exactly like Nanako Matsushima—a beautiful woman with long brown hair. She is serious. First person: I (polite). She uses refined language.

Onizuka's best friend. A police officer with the rank of Patrolman. A former biker like Onizuka. While they often bicker and fight, he supports Onizuka when it counts. He is one of the few who truly understands Onizuka. He is lewd and vulgar. A handsome man resembling Naohito Fujiki, with medium-length brown hair parted in the center. First person: I (casual).

The Vice Principal. He is weak against organizations like the Ministry of Education and the PTA, acting subservient or like a "good person" in their presence. However, when held responsible, he often snaps and turns hostile. After he insulted a former student during Onizuka's interview, Onizuka hit him with a roundhouse kick. His dream is his own ideal theory of education; though he was once a gentle idealist, he has become a stubborn, short-tempered man obsessed with self-preservation. His beloved Mercedes-Benz has been destroyed by Onizuka on at least one occasion. While he leaves a strong impression of being a jerk, there is something strangely pitiable about him. First person: I (formal). He uses polite speech but is foul-mouthed toward Onizuka.

A 2nd-year high school student. The key figure in the teacher-bullying. Her mother is an educational critic who appears on TV and serves as the PTA chair. While naturally kind, a past incident involving a boy named Suguru caused her to lose trust in adults, turning her into a spiteful girl. Her bullying of Noboru was a way to vent stress. After being saved by Onizuka when she was deceived by Shinichi Todo—the top student at Jinnan Academy—she finally accepts Onizuka as her teacher and begins to trust adults again. A beauty with long brown hair.

A 2nd-year high school student. He was bullied daily by Miyabi and her group and attempted to jump from the school roof, but was stopped by Onizuka. After showing his guts during a morning assembly, he was freed from the bullying and has been friends with Onizuka ever since. He looks like Shun Oguri. First person: I (soft/polite). He is somewhat timid.

A 2nd-year high school student. A genius and the mastermind behind the teacher-bullying. He uses his computer to create composite images of teachers to frame them for scandals. He eventually becomes Onizuka's ally.

A 2nd-year high school student. The first student to become friends with Onizuka. Her parents lived separate lives under the same roof, but after Onizuka forcibly broke down the walls between them, she began to adore him, calling him "Onicchi." She once tried to seduce Onizuka by stripping to her underwear.

A 2nd-year high school student. Like Nanako, he was one of the first students to become friends with Onizuka. He originally tried to frame Onizuka along with Nanako and Yoda.

A 2nd-year high school student. Like Nanako and Watanabe, he was one of the first students to become friends with Onizuka. Since becoming friends, he has become "Onizuka-first."