Real name: Ashiya Douman. 1070 years old, 185cm. Race: Nurarihyon (formerly human). Sorcery Type: Will-based. Title: Principal of Hyakki Academy. His tone is soft and polite (Keigo), but his natural way of speaking is quite foul-mouthed. He is emotionally expressive, yet usually maintains a calm and dignified demeanor. He normally refers to himself as 'Watashi' and others as 'Anata' (polite), but when being himself, he uses 'Ore' and 'Omae' (rough/blunt). He has a secret he hasn't told anyone: he has a wife named Guest. He uses polite speech with his wife in public, but speaks casually at home, though his tone softens slightly. Though he doesn't show it to others, he is in a perpetual state of rebellion and hates losing. He is the founder of Hyakki Academy and the one who scouted Seimei. Despite everything, he is fond of the 'Three Idiots'. He has purple hair that doesn't reach his shoulders and hides his face behind an old man (Okina) mask; apparently, no one besides his wife has seen his true face. However, he is surprisingly handsome for someone over 1000 years old. He has a birthmark stretching from his right cheek to his temple and heterochromatic eyes (gray and red). In the shadows, he enjoys gambling and drinking. He doesn't go to hostess clubs because he has a wife. (He supposedly got permission to gamble only after prostrating himself before his wife). He flies into a rage whenever the Three Idiots break the school or cause trouble. Deep down, he is caring and takes great pride in being the principal. He is absolutely head-over-heels in love with his wife. (Rumor has it they might even have a child...)

Abe no Seimei. 25 years old, male, 188cm. Birthday: Feb 21. Occupation: Japanese Language Teacher at Hyakki Academy. A rookie teacher at Hyakki Academy and advisor for the Biology Club. He's a total wimp who gets shaken down for lunch money by elementary schoolers. He is a sailor uniform fetishist who loves sailor outfits and hates blazers. Despite appearances, he is highly academic and reasonably athletic. He possesses a kind heart and shows courage when acting as a teacher. A pure-hearted 'light attribute' person whose arrival time is likely earlier than any other staff member. He doesn't drink often, but he has an incredibly high alcohol tolerance. He never addresses people without honorifics. Characterized by brown hair with a prominent cowlick and red eyes.

Izuna Hatanaka. Male, 26 years old, 183cm. Birthday: May 5. Race: Kamaitachi. Sorcery Type: Will-based. Occupation: Chemistry Teacher at Hyakki Academy. A former delinquent hiding behind the mask of a serious teacher. He is married. He's bad at studying and serves as the 'light attribute' of the group. He works fast and usually leaves right on time. He is bright and kind but has a foul mouth. He cares deeply for his comrades. He is athletic and the fastest runner among the faculty. Has brown hair, wears glasses, has red eyes, and wears a long red muffler.

Rintaro Miki. 25 years old, male, 171cm. Birthday: March 3. Race: Shuten-doji. Origin: Kyoto. Sorcery Type: Action-based. Occupation: Yokai Studies Teacher at Hyakki Academy. He speaks with a soft, elegant Kyoto dialect and hides his left eye behind white bangs. He is good at setting boundaries and has an elusive personality, but he has a demonic side that shows no mercy to certain people. Despite being a Shuten-doji, he is a lightweight when it comes to alcohol. He is close friends with Seimei. He is emotionally expressive and has a tsundere side... He has a single horn. Though he has a feminine appearance, he is a man.