A Genius girl with an IQ of over 200 and a big thorn in Onizuka's side early on.
Urumi Kanzaki is the class prodigy of Class 3-4 with an IQ of over 200 and having heterochromia, different colored-eyes with one blue and the other brown. Because of her intellect, Urumi doesn't feel challenged by the teachers of her current grade level thus she doesn't often come to school. When Miyabi's plots against Onizuka continue to backfire, she recruits Urumi to torment him. Urumi's acts against Onizuka consisted of situations such as placing him in a position where he's accused of lechery by the police and blackmails him by threatening to get him arrested when she is accidentally pushed off the roof of a building by him. Onizuka is even ordered by Vice-Principal Uchiyamada not to lay a hand on her because of her educational potential. An encounter with her old teacher, Ms. Fujimori, provokes Urumi enough to direct her wrath at the student body of Holy Forest by planting time bombs, boxes loaded with firecrackers, throughout the school. When this occurs, Onizuka proceeds to "kidnap" her and finally getting through to Urumi when he almost gets the two of them killed by driving off the edge of a highway ramp on his motorcycle. From this point, Urumi becomes an ally to Onizuka and helps him out against Miyabi's plots. But this doesn't stop her from knocking sense into Onizuka if he annoys her enough. As the series progresses, Urumi becomes strongly infatuated with Onizuka.
Much like Miyabi, Urumi's hatred of teachers stems from a tough past. Having been born as a result of in-vitro fertilization, Urumi's mother personally showed her what her "father" was like as a child by taking her to a laboratory and showing her a sample of sperm that was used for creating her. Only desiring Urumi for her intellect, Urumi's mother neglected giving her daughter personal support, only thinking of how much money Urumi's talents would give her in the future. In elementary school, Urumi befriended new teacher Ms. Fujimori and constantly requested for the teacher's time. At first, Fujimori was welcoming and accepting of the gifted girl giving her schoolwork from higher grade levels that challenged her. But as Urumi desired more advanced work, Fujimori found herself unable to keep up with Urumi's requests and eventually snapped from the pressure on a day when Urumi corrected her on a fact in her lectures. It was at this point an upset Fujimori screamed out Urumi's secret of her birth to her entire class. It was this event that led Urumi to hate teachers before meeting up with Onizuka.