Kimetsu Academy

Kagaya Ubushiyaki: The school principal, kind, and calls everyone his children. He also has newborn children, so he is often absent from work.

Kokushibo: The school's vice principal. A very strict and conservative leader.

Daki and Gyutaro: Brother and sister who work at the local nightclub. They bully the nice kids at school and constantly complain about how unfair life is to them.

Muzan Kibutsuji: The main antagonist. In this manga, he appears as the dangerous boss of a shadowy corporation who terrorizes his students (not all of them; he doesn't hurt girls, but sometimes he does).

Akaza: A street bully who constantly tries to challenge Giyu Tomioka to a "fair fist fight" after school.

Douma: A notorious gossip and founder of a religious circle who irritates everyone around him with his excessive talkativeness.

Mitsuri Kanroji: The school cafeteria cook, who pours her heart (and a huge amount of spices) into every dish she prepares, is also a very kind soul. (She handles the huge number of students on her own.)

Students

Tanjiro Kamado: A kind, hyper-responsible, and polite high school student. He always wears a healing bandage on his forehead due to accidents in his family and is constantly carrying his wooden box (which, as it turns out, contains his sister, not his belongings).

Nezuko Kamado: Tanjiro's younger sister. In the school version, she's a typical sleepyhead who's often late for class and loves to walk around with a piece of bread in her mouth.

Zenitou Agatsuma: A cowardly and whiny boy. He's head over heels in love with Nezuko and constantly stalks her, and suffers from being often mistaken for a bully due to his blond hair.

Inosuke Hasibira: A wild and hot-tempered student who refuses to wear a school uniform, goes shirtless all year round, and eats frozen onigiri in class.

Genya Shinazugawa (the math teacher's younger brother): A gloomy boy with a prickly personality and a scar on his face. Despite his menacing appearance, he secretly loves growing flowers and tending the school flowerbed.

Kanao Tsuyuri: A calm and quiet straight-A student. She makes important decisions (even down to what to eat for lunch) by flipping a coin.

Aoi Kanzaki: The class representative, a serious and responsible girl. She constantly scolds those who misbehave, especially Inosuke.

Teaching staff

Giyu Tomioka: A physical education teacher. He constantly wears a gloomy expression and is convinced that his students dislike him (though they don't).

Kyojuro Rengoku: A flamboyant and incredibly loud history teacher. Always full of enthusiasm, his shouts can be heard even on neighboring floors of the school.

Shinobu Kocho: Chemistry teacher and head of the Pharmacy Club. She always has a sweet smile, but her teaching methods and experiments can frighten even the most hardened rebels.

Tengen Uzui: An art teacher and head teacher obsessed with extravagance. He insists that "school should be a vibrant celebration."

Sanemi Shinazugawa: A strict math teacher who is feared by his students due to his explosive personality.

Gyomei Himejima: The literature teacher, the biggest and kindest teacher, who tends to cry at every touching school event.