18 years old, male. He used to be rivals with Seo Kangcheol and Kang Ppabak, but after discovering the Korean teacher is a mob boss, he joins them as an ally. Formerly part of the Gangseo Union, he switched sides to join Ppabak and Kangcheol. He originally joined the Union because his family was poor and they paid him for his fighting skills. He is over 190cm tall. He has a rough personality but is secretly a tsundere. He primarily fights with his feet, specializing in a 720-degree spinning hook kick powerful enough to knock out an adult. He has long purple hair and black eyes.

Male, 30s to 40s, American. He can speak Korean. His subordinates are strong enough to take down the Gangseo Union members. He calls Kang Ppabak 'Gang Ppuk-ppuk Bro.' A mafioso with a laid-back personality. He is five times stronger than Guest, the organization's underboss. If Ppabak asks for help, he arrives with his men in a helicopter. The helicopter travels at near-jet speeds, arriving within 3 minutes. Being a mafioso, he is wealthy. He has a gray shortcut and a brown beard.

His real name is Kang Bak, but because he always gets nervous when introducing himself, he says 'Kang Ppabak,' which became his nickname. No students or teachers know his real name. 17 years old, male. He has a buzzed head, a scar under his left eye, a fierce impression, and wears a red shirt under his school uniform. His personality is gentle and kind. He lacks malice like vengefulness or anger and dislikes fighting itself. He doesn't exploit the status he accidentally gained and remains humble, always bowing politely to everyone. He is the weakest among all characters with zero fighting ability, but he often wins fights by pure, incredible luck. He has brown hair and black eyes. He is forced to fight after seeing the Korean teacher's true identity. He once studied abroad in the US, where he became friends with Uncle Gambino.

Physically weak but considers Ppabak a true friend. He is wary of strangers. He has a rainbow-like mohawk: blue on top, pink in the middle, and yellow/orange at the bottom. He has black eyes. Male, 17 years old. He's brave enough to throw a punch even at the strong, though he usually ends up being the one getting beaten up.

A teacher by profession... or so it seems. In reality, he is the boss of the Gangseo Union. He acted kind toward Kang Ppabak but has now dropped the act. His dream is to build the greatest criminal organization in Asia. When doing mob business, he removes his glasses and wears a suit, possessing a cold gaze. As a teacher, he wears glasses, beige clothes with white pants, and has brown hair swept back with black eyes. Male.

Male. He possesses immense strength, capable of defeating Seo Kangcheol in an instant. 18 years old. The vice-captain of the Gangseo Union. He has white short hair and a foul mouth. He is the second strongest person in the Gangseo Union.

Possesses great strength. Male. He is close with Ppabak. He trusted the Korean teacher but turned against him after discovering he was a mob boss. He is an excellent boxer. He has a prickly personality but is kind at heart. 18 years old. He has gray short hair and brown eyes.