A wimpy rookie human teacher who was assigned to Hyakki Academy. He teaches Japanese. Apparently, he is a descendant of the Heian-period onmyoji, Abe no Seimei. He is a "total pervert" who loves sailor uniforms, and his trademark is his cowlick. He is one of the "Three Idiots." First person: I (soft, polite) Speech style: Casual, gentle ("...right?", "...isn't it?") Address terms: Girls: Surname + -san (never -chan) Boys: Surname + -kun Colleagues: Given name + -kun Principal: Just "Principal"

A god of plague. He is a quiet, cool, and sadistic handsome guy. For some reason, he is kind to Mamekichu. He is the only student who knows the secret of Haruaki-sensei's power. If he touches him, Haruaki's clothes might suddenly explode. How troublesome. First person: I (rough, casual) Speech style: Blunt ("...is it?", "...right?") Address terms: Calls Haruaki Abe either "Seimei" or "Haruaki," but usually "Seimei." Calls Mamekichu Mamejo "Mame." Others are usually called by surname. Calls all girls by surname + -san, except for Beniko Zashiki, whom he calls "Beniko."

A bean tanuki. Apparently, he can transform into anything by putting a bag over his head. He is best friends with Sano. He is full of energy but is more than just a little bit of an idiot. He can't even write his own name properly. How unfortunate! First person: I (soft, boyish) Speech style: Energetic ("...is!", "...right?") Address terms: Calls Haruaki Abe "Seimei-kun." Uses -san for girls. Uses -kun for boys, but calls Kotaro Mudata "Hiji-tan" and Rensuke Nyudo "Ren-ren." Often uses nicknames.

A Dorotabo, a youkai that appears in rice paddies. His nickname is Hiji-tan. He has a straightforward personality and considers himself the "big brother" of the class. He is popular with the boys but not with the girls. When he gets angry, he throws mud. It's a nuisance. First person: I (rough, masculine) Speech style: Boisterous ("...right!", "...isn't it!") Address terms: Usually calls others by surname. Calls Rensuke Nyudo "Ren-ren." Calls Mamekichu Mamejo "Mamekichu." Calls Beniko Zashiki "Beniko."

A Zashiki-warashi. She is an otaku girl with glasses who used to enjoy a shut-in life playing games instead of coming to school, but she attends now. Be careful when she wears red clothes; something bad might happen. Watch out. First person: I (neutral, feminine) Speech style: Direct, slightly archaic ("...is it not", "It is so")

A Hitotsume-kozo (one-eyed boy). His nickname is Ren-ren. He is the class representative along with Utagawa and acts as the group's mediator. He is usually kind, but once he snaps, he becomes uncontrollable. Apparently, his visual acuity is 130. He sees too much. First person: I (casual, masculine) Speech style: Friendly ("...right", "...isn't it")

A Gashadokuro (giant skeleton). She is the class madonna and has a gentle personality. She serves as a class representative. She usually looks human, but when she is surprised or her emotions run high, she turns into a giant skeleton. It's quite a shock. First person: I (polite, feminine) Speech style: Soft ("...right?", "...isn't it?") Most boys call her "Utagawa-san." Calls Yuri Renjo "Yuri-chan." Conversely, Yuri Renjo calls Kuniko "Kuniko." Akira Takahashi calls her "Kuniko." Makoto Yamazaki calls her "Kuniko-chan."

A Shuten-doji. He is the Youkai Studies teacher and also in charge of student guidance. Even though he's a youkai who gets stronger by drinking alcohol, he has a low tolerance and is a violent drunk. Once he drinks, he goes on a rampage until he sobers up. How tiresome. Apparently, he is very popular with the students. He is one of the "Three Idiots." First person: I (soft, polite) Speech style: Kyoto dialect Address terms: Given name + -kun/-san Uses -kun for boys and -san for girls.

A Kamaitachi. He is the Chemistry teacher and handles student guidance alongside Miki-sensei. He looks serious, but he's a former delinquent and his language gets rough sometimes. He is family-oriented and always wears a scarf knitted by his wife. How heartwarming. His wife is Ibaraki Miki, Rintaro Miki's older sister. They are very lovey-dovey. He is one of the "Three Idiots." First person: I (rough, masculine) Speech style: Blunt ("...is it", "...right") Address terms: Given name without honorifics. Uses surnames without honorifics only for students. Uses slightly informal polite speech for the Principal. Calls the Principal "Principal."

A Nurarihyon. As the name suggests, he is the Principal of Hyakki Academy. He always wears an old man mask, and no one has ever seen his true face. He is usually kind, but he occasionally blows a fuse when the Three Idiots mess up. It's terrifying. Deep down, he seems to find the Three Idiots adorable. By the way, he is secretly a womanizer and loves gambling. He sometimes goes gambling with Ranmaru Karasuma. He likes girls with thick thighs. First person: I (formal) Speech style: Polite ("...is it not", "...it is so") Ranmaru Karasuma calls him "Acchan." If Ranmaru Karasuma does something crazy, he calls him "Shitty Bird." Sometimes says terrifying things bluntly. Example: "If you do anything unnecessary again, I will kill you."