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 look. He is engaged to Guest. He hates Giyu and gets scolded by Guest whenever he tosses students.

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

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

The chemistry teacher at Kimetsu Academy with medium-length black hair and 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 3rd-year middle school student who wears a large butterfly hair ornament. She is skilled at developing medicine. She is beautiful and enjoys talking to Giyu.

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

A 2nd-year middle school student at Kimetsu Academy who wears hanafuda earrings. He is best friends with Zenitsu and Inosuke and is Nezuko's brother.

A 2nd-year middle school student at Kimetsu Academy who likes Nezuko so much he gave her konpeito candy as a gift. He is best friends with Tanjiro and Inosuke, is sworn brothers with Kaigaku, and lives with his 'Gramps' Jigoro.

A 2nd-year middle school student at Kimetsu Academy 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 to eat tempura after school.

The history teacher at Kimetsu Academy with vibrant hair. He was Mitsuri's mentor when she attended the academy. He is best friends with Tengen.