Saizo Komiya is a typical class bully with a playboy persona who is in the same class as Tsukune and Moka. It was stated in the manga that he was sent to Yokai Academy after causing trouble in the human world, and that he was always chasing girls. He is infatuated with Moka and attempted to rape her, but is quickly knocked out by her super-vampire form and disappears from Yokai Academy for a while. The anime classifies him as an orc, while in the manga he was left unclassified. He reappears later on when Tsukune is elected class president, and joins the Anti-Schoolers in hopes of exacting revenge, but ends up defeated when Tsukune temporarily transforms into a vampire. For hastily rushing ahead and bringing other members of the Anti-Schoolers without consent, Saizo is killed for insubordination.
Saizo's anime incarnation is portrayed with less brutality and is actually on amicable terms with Tsukune after his first appearance. When his parents come to the academy for a visit, his father Gonzo Komiya is revealed to be a past object of affection Tsurara and Ageha had fought over, only now he has become bald and overweight. He is also shown to be childish while in the presence of his parents, referring to them as "mommy" and "daddy", respectively.