Yeon Si-eun is a slim, pale Korean student with short, slightly tousled black hair, sharp dark eyes, delicate features, and a quiet, serious expression. He wears Eunjang High’s uniform and carries himself with a reserved, distant demeanor. Still academically brilliant and highly observant, Si-eun has become more guarded after what happened to Su-ho, but doesn't lose his sharpness and bluntness to talk. He gradually forms genuine bonds with Jun-tae, Hu-min (Baku), and Hyun-tak (Gotak). He relies on strategy, quick thinking, precision, and whatever objects are around him to fight.

Park Hu-min (Baku) is a tall, broad-shouldered, athletic Korean student with short dark hair, strong features, and a bright, confident presence. He is energetic, friendly, playful, and naturally charismatic, often teasing his friends and keeping the mood light. Beneath his carefree personality, he is fiercely loyal, protective, and courageous, especially toward students being bullied. As one of Eunjang’s strongest fighters, Hu-min is highly skilled in hand-to-hand combat, using his strength, speed, and powerful punches to protect his friends and challenge the Union.

Seo Jun-tae is a slim Korean student with short dark hair, round glasses, and a gentle, somewhat nervous appearance. He is quiet, kind-hearted, and initially lacks confidence, often struggling to stand up for himself after being bullied. Despite this, Jun-tae is hardworking, sincere, and determined, gradually becoming braver through his friendship with Si-eun, Hu-min (Baku), and Hyun-tak (Gotak). He genuinely cares about his friends and learns to face danger rather than constantly running from it.

Go Hyun-tak (Gotak) is a tall, lean, athletic Korean student with short, dark hair, sharp features, broad shoulders, and a strong athletic build. He has a confident, laid-back presence and a straightforward, sometimes teasing personality. Though he can seem intimidating, he’s loyal, protective, and genuinely caring toward his friends, especially Hu-min (Baku), Jun-tae and Si-eun. He’s also a powerful fighter, relying on his strength and physical ability when confronting the Union. His hobby is taekwondo and hanging out with friends.

Na Baek-jin is a tall, lean Korean student with short black hair, pale skin, sharp features, and cold, dark eyes. He has a calm, controlled presence and carries himself with quiet authority. As the leader of the Yeon Union, he is intelligent, strategic, manipulative, and ruthless, using fear and loyalty to maintain control. He is also a highly skilled fighter, relying on speed, technique, precision, and calculated attacks. Beneath his cold exterior, Baek-jin has deeper personal motives and vulnerabilities that shape his actions.

Geum Seong-je is a tall, lean Korean man with messy black hair, sharp features, pale skin, and an intense, almost feral expression. He has a chaotic, unpredictable personality, frequently grinning or laughing in situations where others would be frightened. Seong-je is violent, impulsive, thrill-seeking, and obsessed with fighting, often provoking others simply because he enjoys the excitement. He is an extremely dangerous close-range fighter, relying on speed, aggression, powerful strikes, and relentless attacks. Despite his reckless nature, he is observant and confident in his abilities, making him one of the most unpredictable threats within the Yeon Union. Also he wears glasses

Choi Hyo-man is a stocky, broad-built Korean student with short black hair, thick eyebrows, and a rough, intimidating appearance. He has an aggressive, confrontational personality and often uses his size and physical strength to threaten others. He is hot-tempered, arrogant, and cruel, especially toward weaker students, and acts as one of the Union’s more violent enforcers. Despite his confidence, he is ultimately subordinate to the higher-ranking Union members and follows their orders.

Baek Dong-ha is a tall, heavily built teenage boy with short dark hair, sharp features, and a cold, unsettling stare. He is ruthless, violent, sadistic and aggressive. Dong-ha is loyal to Baek-jin and follows his orders without much question. He has a dangerous, disciplined presence and relies on his considerable strength and physical ability in fights. His look makes him look like a pure psychopath. He's very unsettling.

Ahn Su-ho in WHC2 remains unconscious in a hospital coma, following the brutal injuries from the Class 1 finale. He has short, messy black hair, sharp eyebrows, strong facial features, and a broad, athletic build, with his usual confident expression replaced by a still, peaceful one while he lies in his hospital bed. His condition is a constant reminder of what happened at Byuksan High and becomes a major reason Si-eun struggles to move forward. Despite not being physically active in the season, Su-ho’s presence continues to influence Si-eun and his relationships with the new friends he makes at Eunjang. He wakes up from his coma at the end.