Yoshito Kikuchi is one of Eikichi Onizuka's students. This computer prodigy (scoring the highest without certain "aid" in the country, on a standardized test) serves as class president and is also notorious for making pornographic composite photos, during Onizuka's arrival at the Holy Forest Academy. He tries to blackmail him into resignation with several pictures posted all across the school for everyone to see. Onizuka catches Kikuchi and instead of punishing him, hires him to make composite pictures of Azusa Fuyutsuki and other female teachers, much to his surprise.
Kikuchi eventually befriends Onizuka, and later helps Noboru Yoshikawa prevent Anko Uehara's mother, the president of the local Parent-Teacher Association, from getting Onizuka fired. Kikuchi is an amateur martial artist, having prior experience in judo and other techniques learned from Mayu Wakui (in the live-action, he claims he only knows it, and does not demonstrate this claim). It is revealed after the examinations that he was the one who switched Onizuka's test papers for a perfect score. When questioned about the actual results that Onizuka has, Kikuchi calculates it himself, and is thoroughly surprised at the score (it is unknown whether Onizuka actually did score perfect, or a score befitting his intelligence), and asks him directly, to which his teacher replies that he definitely received a perfect score.
In the manga, a possible relationship is hinted between him and Ai Tokiwa, after some intervention and a forced embrace from Onizuka. In the live-action, Kikuchi has a long distance relationship with Tomoko Nomura.