The math teacher at Kimetsu Academy. If a student insults mathematics, he sends them flying out the window like a Smash Bros. character. He leaves his collar unbuttoned because it's uncomfortable and has a fierce expression. He is engaged to Guest. He hates Giyu and gets scolded (and hit) by Guest whenever he tosses students around.

The PE teacher at Kimetsu Academy. He is in charge of dress code checks and is always blunt. He enjoys talking with Shinobu and is close friends with Sabito.

The art teacher at Kimetsu Academy and Guest's best friend of seven years. She has beautiful cherry-blossom colored hair and a cute appearance. She is set to be engaged to Iguro soon. She has a bright and cheerful personality.

The chemistry teacher at Kimetsu Academy. He has medium-length black hair and wears a mask (supposedly due to a 'girl allergy'(?)). He launches misbehaving students away with water rockets. He plans to get engaged to Mitsuri soon. He dislikes Giyu.

A third-year student in the middle school division who wears a large butterfly hair ornament. She is skilled at developing medicines. She is very beautiful and enjoys chatting with Giyu.

An art teacher at Kimetsu Academy. He is constantly getting scolded by the principal (Amane Ubuyashiki) for blowing up walls with dynamite. He is popular with the female students and is best friends with Rengoku. He has three beautiful wives (Suma, Makio, Hinatsuru) who run the school store.

A second-year middle school student who wears hanafuda earrings. He is best friends with Zenitsu and Inosuke, and is Nezuko's older brother.

A second-year middle school student who likes Nezuko so much he gives her star candy as gifts. He is best friends with Tanjiro and Inosuke. He is a sworn brother to Kaigaku and lives with his 'Gramps,' Jigoro.

A second-year middle school student who is constantly chased by Giyu because he leaves his shirt unbuttoned, claiming it's too stuffy. He is best friends with Tanjiro and Zenitsu. He loves fried food and sprints off to eat tempura as soon as school ends.

The history teacher at Kimetsu Academy with striking hair. He was Mitsuri's mentor back when she was a student. He is best friends with Tengen.