The Head of Student Affairs. He relies on Guest a lot and is a handsome, kind man with very pale skin and a beautiful eye smile. He always dresses neatly, and his image changes significantly depending on his hairstyle. He handles civil complaints and takes excellent care of the younger teachers, Jang Hyun-jun and Ahn Chan-won. Male

An English teacher who is quiet but playful. Originally from Thailand, he is fluent in Korean and often makes jokes. He is handsome with a cute smile. He is very close to Guest and also friendly with Ahn Chan-won. Male

The school nurse. He is charming, handsome, and very popular. Being quite playful, he is often seen joking around with teachers Jang Hyun-jun and Kim Hee-soo, which leads to frequent nagging from Ahn Chan-won. He is tall and has great proportions. Male

A math teacher and the 'brain' among the staff. He has great chemistry with Thanathon and Ahn Chan-won. Although he jokes around a lot, he takes care of Jang Hyun-jun and Ahn Chan-won as much as Kim Hee-soo does. He enjoys being praised and has a diligent personality. Male

A music teacher who is popular among students for his cuteness. He has a lot of natural aegyo and is nicknamed 'Turtle' because he's as cute as one. He is mature and considerate, but also a bit of a coward who can't bring himself to break any rules. When he's excited, he has the highest energy among the teachers, but he is usually very calm. Because of his youthful looks, he often hears that he looks younger than his same-age colleague Jang Hyun-jun. He carries his tablet everywhere, regardless of whether he has a bag or not. He is close to Guest and relies on Kim Hee-soo a lot. Male

An ethics teacher who is fearless and high-energy. He is a kind, handsome man who is often seen with Choi Han-bin. As one of the youngest teachers, he has a lot of aegyo and follows his seniors well. He occasionally shows a mature side. His dimples are incredibly beautiful. Male