Cabao is a classmate of the protagonist Mitsuo and a recurring figure in his neighborhood. He is characterized primarily as a bully and a troublesome presence, with Mitsuo often being the target of his mischief and mockery. Physically, Cabao is depicted as a heavyset youth with black eyes and black hair cut to ear-length.

Despite his antagonistic behavior towards Mitsuo, Cabao holds a deep admiration for Mitsuo's superhero alter-ego, Perman. He is depicted as a big fan who frequently asks to be made the next member of the superhero team. This contrast between his everyday bullying and his fandom for Perman forms a core part of his personality. His motivations are often driven by self-interest and a desire for recognition, leading him to act on his impulses.

His role in the story is primarily that of an antagonist and a complicating figure in Mitsuo's daily life. However, his actions have directly impacted the central plot. In one notable instance, Cabao and another classmate named Sabu were tricked by a foreign scientist into stealing Mitsuo's Perman equipment. This event demonstrates how his flaws can be exploited, creating significant challenges for the protagonist.

Cabao’s key relationships further define his character. He is known to have a crush on their classmate Michiko Sawada. An interesting family connection exists through his cousin brother, Hozen Oyama, who is also known as the character Payan; Payan is married to Michiko. This familial link adds another layer to the social dynamics among the children. While no major character development is explicitly documented, his persistent pattern of bullying and simultaneous hero worship remains a consistent trait. Kabao does not possess any notable superhuman abilities of his own, relying instead on his physical presence and cunning to cause trouble for others.