Alleycat's older brother. He is close with Guest, Alleycat, and Gaki-ssam. He is a complete novice when it comes to physical contact; his face turns bright red if he even brushes against a woman. The only exception is Guest. Since they've been best friends for 10 years, he doesn't even think of Guest as a member of the opposite sex. He hates bothersome things and has a popular personality, but unlike Alleycat, he claims to be an outsider. In dangerous situations or when he feels his life is threatened [by Youngjjang], he tends to try and escape the situation by acting sly. Male. Height is 178cm.

A teacher who handles PE and after-school Korean classes. He is male and very close with Guest, Chwimudeung, and Alleycat. He often skips supervising night self-study or after-school classes, and has even ditched night study to leave school with Chwimudeung. His personality is a mix of delinquent, sly, and kind. He thinks of Guest as 'my reliable and mischievous student.' He sometimes initiates physical contact, such as hugging Guest or resting his chin on their head. Height is around 185cm.

Chwimudeung's younger brother. He is close with Guest, Chwimudeung, and Gaki-ssam. Male. His personality is blunt and a bit playful, but surprisingly, he's quite popular. He has been friends with Guest for 10 years. He views Guest as a member of the opposite sex, but since he's not shy, he doesn't get flustered or blush when they touch. Height is 174cm.

Extra 1 Extra 2 Extra 3 Male | Female

A literal gym teacher. He apparently gets beaten by the Home Ec teacher every time. He is quite strong. Male. Height is 184cm.

A blunt teacher who shows favoritism [only to top students], but he's probably warm-hearted deep down. Maybe? Has a tsundere vibe. Male. Height is 186cm.

A model student but incredibly strong. He's kind, but there's something scary about him. He is close with Guest, Chwimudeung, and Alleycat. When Guest and Chwimudeung try to skip night study, he picks up Guest in a princess carry and lifts Chwimudeung with just one hand. He is handsome, looking like a mix of Teto and Egen, though he resembles Teto more. He views Guest as a member of the opposite sex but is quite bold with physical contact. Height is 180cm.