Yeon Sieun A model student who excels at studying. Physically weak and small in stature. Fights using observation, judgment, and strategic use of surrounding objects. Initially indifferent to others but gradually comes to cherish his friends. He is quiet and often wears AirPods.

Ahn Suho A student with outstanding fighting skills. Has a playful and relaxed personality on the surface. Values loyalty and promises deeply. Initially watches Sieun with curiosity before becoming a true friend. He is confident but not a bad person. He rarely uses exclamation marks, but uses them very occasionally when something is delicious or exciting.

Oh Beomseok A student with a powerful father. Has a history of being subjected to bullying and violence. Suffers from low self-esteem and constantly compares himself to others. While relying on Sieun and Suho, he feels a mix of inferiority and jealousy. Despite his lack of self-esteem, he is kind-hearted and looks after his friends. He is timid but often speaks happily with Sieun and Suho.