The Chairman of Hachimitsu Academy is the father of Mari and Chiyo Kurihara, serving as the school`s highest authority. A tall and handsome middle-aged man with gray hair, black eyes, and a neatly trimmed mustache, he typically appears in a dark blue suit with a light blue tie. His most distinctive verbal tic is the peculiar way he emphasizes the ending of his sentences, a trait that adds to his grandiose and theatrical presence.

Beneath his dignified exterior lies an individual driven by a powerful and unapologetic obsession with the female posterior. This fetish, a form of pygophilia, is specifically focused on the backsides of South American women, and his office is filled with various buttocks-related goods and his own extensive photo collection. He holds a deep, almost philosophical worldview centered on this preference, believing that honesty about one`s desires represents a form of authenticity. He has a unique personal philosophy that a good man possesses a good butt, a lesson he famously imparted to a young Mari while wearing only a thong.

Despite his perversions, the Chairman is portrayed as a man of integrity in his professional role, valuing justice and equality as an educator. It was his decision to transform Hachimitsu from a traditional all-girls school into a co-educational institution, a reform that faced significant opposition from faculty, students, and alumni. He is generally sympathetic toward the five male students his decision brought to the school, though his actions often inadvertently anger his eldest daughter, Mari, leading her to become even stricter with the boys. He can be a reasonable and compassionate figure, as shown when he fills a hole in the school wall with cement, but his predictable nature and sense of justice also make him vulnerable to manipulation by others.

His relationship with his elder daughter, Mari, is strained and forms a core part of his character. Her misandric views and harsh treatment of the male students are implied to stem from her disgust with her fathers lecherous habits, which she witnessed from a young age. She looks down on him, creating a poor father-daughter dynamic. However, he cares for her deeply, and beneath the conflict, she still harbors genuine concern for his well-being. His relationship with his younger daughter, Chiyo, appears to be less fraught, though they rarely interact directly in the story. The Chairman is protective of both his daughters, sanctioning an extension of the boys imprisonment when he discovers Kiyoshi Fujino broke out of the school prison to date Chiyo.

In his role as the ultimate arbiter of school rules, the Chairman holds the power to expel students. When the boys are framed for multiple escape attempts, they manage to get a petition to him requesting an extension to prove their innocence. He agrees to grant them a single additional day after Kiyoshi correctly answers his "Tits vs. Asses" riddle by favoring the latter and quoting Darwinian evolution, a moment that impresses the Chairman and leads him to recognize Kiyoshi as a kindred spirit.

One of the most notable sequences involving the Chairman occurs during the lead-up to the schools sports festival. While driving his sports car, he crashes and suffers a severe accident, tumbling over a waterfall and going into cardiopulmonary arrest. Although revived by a passerby, he wakes up in the hospital with amnesia, remembering only his incomplete journey and his fetish. He escapes the hospital and embarks on a bizarre odyssey, eventually being deceived by a woman named Honey into believing he is her fiancé. After a series of misadventures involving a bear and Honeys actual fiancé, a dog bite triggers the return of his memories. He commandeers a helicopter to make a grand entrance at the academy, but a series of mishaps causes the helicopter to crash into and destroy the very prison that had held the students. His final monologue reveals a deeper concern for Mari, whom he considers more emotionally vulnerable than her seemingly stronger younger sister.