Kizao Kiza, Shota Ohara's elementary school classmate, stands 127 centimeters tall. His family's significant wealth leads him to frequently display new possessions, though this often results in unintended complications. He shares a complex relationship with class bully Tsuyoshi Saigo, known as Godzilla. Kiza addresses Saigo as "boss" while fearing him, creating a dynamic where force isn't consistently applied against him. This fear drives Kiza to ingratiate himself with Godzilla despite the bullying.

Academically, Kiza achieves either perfect scores of 100 or failing scores of 0 on assessments at will. Without corrective eyewear, his severely impaired vision renders him practically blind. He also harbors a documented fear of heights. Within Shota’s class, Kiza maintains friendships with Shota Ohara, Hakase (nicknamed "Professor"), Yoshiko Koizumi (called "Yotchan"), and the ghost characters Q-Taro, P-ko, O-jiro, Doronpa, and U-ko. His mother is identified as Mrs. Kiza.

Across all official franchise media, his character remains consistent with no significant alterations or evolution. His role consistently revolves around his wealthy background, academic fluctuations, and social interactions within the group dynamic.