Kizao appears as Hiroshi Ichikawa's classmate in the 1980 *Kaibutsu-kun* anime adaptation. He belongs to Hiroshi's school peer group alongside Ako and Banno. His presence helps establish Hiroshi's ordinary school environment, contrasting with the supernatural elements introduced by the Monster Prince and his companions. Kizao's name coincidentally resembles a character from *Obake no Q-Taro*, another work by creators Fujiko Fujio, though no direct connection between the series is indicated.

Kizao lacks substantial background, family history, defined personality traits, or character development within the *Kaibutsu-kun* anime series, functioning solely as a supporting figure in Hiroshi's school life scenes.

The character is absent from the original 1965-1969 manga, the 1968 anime, the 2010 live-action television drama, and the 2011 live-action film *Kaibutsu-kun: The Movie*. He also does not appear in related anime films like *Kaibutsu-kun: Invitation to Monster Land* (1981) or *Kaibutsu-kun: The Demon Sword* (1982), confirming his role is exclusive to the 1980 anime.

No official source material details Kizao's involvement in spin-off media, OVAs, alternative narratives, character arc, relationships, or any development beyond his basic function as Hiroshi's classmate.