Onigawara acts like a stereotypical delinquent, being quick to anger and mainly using violence to resolve conflicts. He is quite prideful and cares a lot about his reputation, trying to come off as cool and threatening as possible. He is not above using others to obtain what he wants. However, he has a secret soft side and is really a good kid deep down. Despite acting like a delinquent, Onigawara does not smoke and once had a perfect class attendance record for two consecutive years.