Principal Narunaru is the principal of Jinbou Elementary, while his twin-brother of the same name is principal of Jinbou Middle School. They are both extremely lighthearted and rarely become angry, seeking peaceful solutions to problems. They are both popular among the students, as well as unpopular among the teachers due to their overly light punishments they give out. Two teachers in particular, Sumirei Ando of the elementary and Sengoku of the middle school dislike their respective principals.
Both can be serious at times, but a rarely so, and often snap back into happiness quickly when they are not. It was by the first principal's advice that Hayama take karate, after he attacks him quite weakly.