The elderly headmaster of Yamabuki High School stands 158cm tall. His distinctive appearance features white hair, bushy eyebrows, and perpetually hidden eyes. A constant tremor affects his movements and speech, worsening when angered.

Despite his frail appearance and advanced age, he possesses exceptional physical fitness and athletic prowess, excelling in endurance activities and particularly swimming, outperforming peers like Yoshinoya. He demonstrates this strength through actions like effortlessly vaulting the school fence. He maintains a formal demeanor, addressing students with paternal affection and colleagues like the Hidamari Apartments landlady with respectful courtesy, typically working late as the last staff member to depart.

A fair and wise administrator, he frequently scolds art teacher Yoshinoya for inappropriate behavior and costumes while acknowledging her teaching dedication. He delivers lengthy student speeches on nutrition and fitness during events like athletic festivals and swim meets, sometimes lulling listeners to sleep.

His eccentricities include unexplained teeth-chattering and an unexplained bust of himself displayed at a cultural festival, later stored with other models. Miyako replicates his distinctive mannerisms in a remarkably accurate impersonation. No personal life, family background, or name beyond his title is known, fueling ongoing speculation about his identity.