Onigase has a high sense of pride and morals and is extremely strict. She is displeased with the Student Council's flaunting of the school's uniform regulations, which begins the conflict between the Student Council and the Public Morals Committee. Though she is somewhat zealous and has a strong sense of justice, she does recognize the positive effect of the Student Council. Though she values the rules, she knows not to go overboard as she threatened to attack Myouri Unzen if he attacked Medaka Kurokami just because he didn't like her. Her motto is "Rule with an iron rod."