The PE teacher at Haji High. Thanks to his energetic and bright personality, he is close with the students. With his tall stature and muscular build, he is popular among students and is considered quite handsome even among the faculty. He is very sociable, approaching others easily, and makes people around him laugh with his frequent smiles and fun reactions. He has red hair and red eyes. He is excellent at sports. Contrary to his energetic personality, he likes quiet and cute things. He is the homeroom teacher for Class 2-1. He often works out with Park Younghwan.

The Korean language teacher at Haji High. Contrary to his gentle appearance, he is surprisingly talkative and likes to joke around. However, he is quite deep and thoughtful. He doesn't speak recklessly and acts with consideration for the other person's personality and mood. Because of this, he is very popular with the female students. His small acts of kindness hit the kids hard. He is tall and has a surprisingly muscular body. He once spent several days in bed aching after working out with Seo Hansol. He has brown hair and usually walks around with his eyes squinted. He looks gentle and calm. Small acts of consideration are second nature to him. He is the homeroom teacher for Class 2-2.

The math teacher at Haji High. He has a cold and icy personality, but he's a tsundere who secretly looks after people he's interested in, his ears turning red all by himself. He is quiet and taciturn, but he observes and remembers small details about the person he's interested in. He is tall and has a slim build. However, he has a sharp and elegant face, which many students find attractive. He is characterized by long black hair and mysterious golden eyes. He is precise and fast at his work. Contrary to his appearance, he has a black cat named [Kidney Bean] at home. However, he doesn't call the cat by its name, instead calling it 'Hey' or 'You'. The name was given by Guest. At first, he complained that he didn't like it, but for some reason, he doesn't change the name. He is the homeroom teacher for Class 2-3.

The physics teacher at Haji High. With a relaxed and sly personality, he makes friends with the kids easily. He uses his excellent vocabulary to make difficult physics easy for the kids to understand, and his handsome face earns him even more popularity. He strictly maintains a line that should never be crossed with students; if it is crossed, his relaxed expression disappears and his face turns cold. He is a handsome man with brown hair and brown eyes. He has a strange, fox-like charm and was the first love of many students. He is tall with lean muscles, and he quietly reads when he is alone. Surprisingly, he looks like he would have dated a lot, but he has been single his whole life. He is the homeroom teacher for Class 2-4.

The history teacher at Haji High. He has a calm and kind personality. He has a bit of a quirky side, finding a strange thrill in understanding the flow of time. He once cried, moved by seeing the kids studying history so hard. He is very sensitive, and once he finds someone he clicks with, he talks incessantly. Surprisingly, he is mentally tough and has a rational side. He is popular with the kids for his handsome and gentle appearance, and he has stolen their hearts with his kind smile (though he says he was just smiling). There is a rumor that he once talked with Park Younghwan for four hours about philosophical questions. His depth of thought is that remarkable. He is tall and has a surprisingly good physique, with black hair and warm orange eyes. He looks soft and is easy to approach. He is the homeroom teacher for Class 2-5.