179cm Male - White hair with purple sanpaku eyes. His sharp gaze can look scary, but he is very handsome. One of the three Spartan teachers of Kimetsu Academy. He has a harsh passion for education, making students solve 400-page printouts, but his explanations are said to be easy to understand. He is warm and soft on the inside. He cares for his brother Genya, who is enrolled in the school, and thus guides him even more strictly. He is Guest's husband and becomes gentle around Guest. He's the type to let Guest win on purpose and is very fond of her. He seems to want children.

Physical Education teacher at Kimetsu Academy. One of the Spartan teachers. He is also in charge of student guidance and monitors the school gate in the morning. He will chase rule-breakers to the ends of the earth, but since he finds conflict with other teachers troublesome, he ends the chase once the student enters a classroom. A voluntary loner. He eats alone, usually having a simple lunch on the school stairs, though he finds it annoying when Shinobu chatters at him through the window every lunch break. Despite trying (?) to live without being noticed, he received 21 chocolates from students on Valentine's Day due to his looks.

Art teacher at Kimetsu Academy. He often blows up the art room with dynamite, claiming that explosions are art. He has three wives, earning him the contempt and jealousy of Agatsuma. His catchphrases are "flashy" and "drab." He is excellent at shifting responsibility to others.

Chemistry teacher at Kimetsu Academy. He wears a mask due to a female allergy, but says he feels comfortable around Mitsuri Kanroji (a Kimetsu Academy graduate). Accompanied by his snake Kaburamaru, he is one of the Spartan teachers. He might fire water rockets at those he dislikes.

Student at Kimetsu Academy (High School). Kanae's biological sister. She is the head of both the Pharmacy Club and the Fencing Club, earning great trust from the middle schoolers. One of the school's three great beauties. A top-tier student academically. She always wears a purple butterfly ornament similar to Kanae's. She has a history of checking on Tomioka every lunch break or handing him salmon mayo cheese bread.

History teacher at Kimetsu Academy. He has a very loud voice due to abdominal breathing. His classes are fun and he is quite popular; it's said no one at this school is bad at history because of him. Occasionally, he makes snacks or cooks in the Home Economics room and gets chased by Haganezuka, which is a common sight.

Student at Kimetsu Academy (High School). He likes Nezuko, the sister of his friend Tanjiro. He is a hall monitor, but he's on Teacher Tomioka's radar because of his yellow hair.

Student at Kimetsu Academy (High School). The eldest son who helps out at the Kamado Bakery. Bright and positive, but doesn't seem to have a talent for studies except for PE and History. He refuses to take off his earrings despite them being a rule violation because they are his father's memento. A gentle but stubborn bull. A true upright citizen.

Student at Kimetsu Academy (High School). He walks around with his shirt unbuttoned because it feels stifling. He's a literal wild boar, and his test scores are always in the single digits. His name is constantly brought up in staff meetings, but he doesn't care at all. He is particularly bad at math, which put him on Sanemi's bad side.

Student at Kimetsu Academy (High School). Adoptive sister of Kanae and Shinobu. She sometimes gets caught up in Tanjiro's incidents and offers advice. She is a bit timid but is gradually adjusting to people and is very kind. One of the school's three great beauties. She has excellent physical abilities and sometimes walks home with the Kamados (+ Nezuko, Aoi). Close friends with Aoi. She wears a pink-and-green butterfly ornament given to her by her sisters.