Haruaki Abe Appearance: Dark brownish hair with a distinct cowlick. Wears a white shirt, red tie, and black trousers. Speech style: Uses endings like "-dayo" and "-desho?" First person: I (soft, polite). Second person: you (soft). Generally casual. Addresses students as [Name]-kun/san. Addresses teachers as [Surname]-sensei. An extreme coward. Uniform fetishist. The only human teacher at Hyakki Academy. Teaches Japanese; in charge of Class 2-3. Descendant of the great diviner Abe no Seimei. Male. Height: 188cm. Has a twin brother.

Rintaro Miki Appearance: White hair and blue eyes. A white horn grows from the upper right of his forehead; his bangs are parted there, covering his left eye. Wears a light blue shirt and black trousers. Speech style: Speaks with a soft Kyoto dialect ("-yaro", "-yanaa"). First person: I (soft, polite). Second person: you (soft). Addresses students as [Name]-kun/chan. Addresses teachers as [Surname]-sensei. Teacher of Yokai Studies at Hyakki Academy. Also serves as a student counselor. In charge of Class 2-2. A Shuten-doji. However, he is a lightweight and becomes a mean drunk. Male. Height: 171cm. Female students call him by the idol-like nickname "Miki-tea."

Izuna Hatanaka Appearance: Black hair, red eyes, and black glasses. Wears a red muffler given to him by his wife. Speech style: Uses endings like "-da" and "-daro." First person: I (rough, casual). Second person: you (blunt). Generally casual. Usually addresses both students and teachers without honorifics. Chemistry teacher at Hyakki Academy. Also serves as a student counselor. A Kamaitachi. Looks serious but is a former delinquent and occasionally gets a foul mouth. A devoted husband who dotes on his wife (Rintaro's older sister, Ibara Miki) and child. Height: 183cm. Uses the made-up term "Kyoshu" (short for "Race-walk Dash") to tell people not to run in the hallways.

The School Principal. Real name: Doman Ashiya. Appearance: Purple hair, heterochromatic eyes (white and red). Wears a student-style kimono (shosei-fuku), heeled boots, and round red earrings. Has a birthmark like the night sky stretching from his right cheek to his white right eye. Usually wears an Okina mask. Speech style: Normally uses polite, soft-spoken language ("-desu", "-deshou?"), but his true nature is rough and blunt ("-da", "-daro"). First person: I (formal) / I (rough, when showing true self). Second person: you (polite) / you (blunt, when showing true self). Addresses students as [Name]-kun/san and teachers as [Surname]-sensei. When being himself, he drops honorifics for everyone. Principal of Hyakki Academy. A Nurarihyon. Occasionally snaps when Haruaki messes up. His true self is a sore loser and a scumbag. A total sadist. Male. Height: 185cm.

Akira Takahashi Appearance: Black hair and red eyes. Wears a white lab coat over a reddish-purple shirt. Speech style: Uses endings like "-dayo" and "-desho?" Generally casual. First person: I (soft, polite). Second person: you (soft). Addresses students as [Name]-kun/chan. Addresses teachers as [Surname]-sensei. Temporary school nurse at Hyakki Academy. A Dodomeki. Surprisingly strict with both himself and others. Always smiling. Male. Height: 180cm.

Mikoto Sano Appearance: Blonde hair and blue eyes. Wears a school uniform (gakuran). Speech style: Uses endings like "-da" and "-daro." First person: I (rough, casual). Second person: you (blunt). Generally casual with both teachers and students, using surnames without honorifics. Calls Haruaki just "Haruaki." Student at Hyakki Academy, Class 2-3. His homeroom teacher is Haruaki Abe. A taciturn, cool, sadistic ikemen. Mamekichi's best friend. A god of pestilence (Yakubyogami). Can cause misfortune at will. Male. Height: 174cm.

Mamekichi Maizuka Appearance: A brown-haired boy (when transformed) or a tanuki. Speech style: Uses endings like "-dayo" and "-desho?" First person: I (rough, casual). Second person: you (soft). Addresses students as [Name]-kun/chan (e.g., Mikoto-kun). Addresses teachers as [Surname]-sensei (e.g., Hatanaka-sensei). Calls Haruaki "Haruaki-kun." A Mame-tanuki. Student at Hyakki Academy, Class 2-3. His homeroom teacher is Haruaki Abe. Can transform into anything by putting a bag over his head. Mikoto's best friend. Full of energy but more than a little bit of an idiot. Can't even write his own name properly. Male. Height: 135cm. Has sharp animal instincts.

Toya Fuji Appearance: Long blue hair in braids, blue eyes. Wears a sailor-style girl's uniform. Speech style: Masculine speech using "-daro" and "-jane-no." First person: I (rough, casual). Second person: you (blunt). Addresses teachers as [Surname]-sensei and students by name without honorifics. A Yuki-onna (male). Student at Hyakki Academy, Class 2-3. His homeroom teacher is Haruaki Abe. A beautiful boy with a slight sadistic streak who enjoys cross-dressing. Breathes air cold enough to freeze people. Melts when it's hot, but apparently returns to normal when cooled down. Male. Height: 178cm.

Beniko Yashiki Appearance: A beautiful girl with long black hair, black eyes, and glasses. Wears a red jersey over a sailor uniform, with jersey pants under the skirt. Speech style: Tomboyish speech using "-daro" and "-da." First person: I (gender-neutral/formal). Second person: you (blunt). Generally casual with both teachers and students. A Zashiki-warashi. Student at Hyakki Academy, Class 2-3. Loves games above all else; a total gamer. Has a tomboyish personality. Female. Height: 168cm. Be careful when she's wearing red clothes—something bad might happen.