Chieko Sannomiya is the eponymous principal of the Seito Sannomiya Private School. She was appointed office a decade prior to the story and carries herself in a conceited, yet formal, aristocratic manner. As a radical misandric, Sannomiya heavily supports feminism and irrationally views males as barbaric. At the conclusion of the series it is revealed that an incident between a man (hinted by Lulu) and her lead to her sexist ideology.

(Source: Wikipedia)