Ahn Su-ho is the strongest student at school, but he only fights to protect others. After witnessing the quiet, intelligent Yeon Si-eun outsmart bullies despite being physically weaker, Su-ho befriends him. His easygoing nature helps Si-eun slowly open up, and the two form a genuine friendship. They later welcome the timid Oh Beom-seok into their group. For a time, the three enjoy the friendship Beom-seok had always wanted, while Su-ho tries to support them both without asking for anything in return. However, Beom-seok’s fear of being left behind grows into jealousy. Unable to overcome his insecurities, he betrays Su-ho by arranging for him to be ambushed by multiple fighters. Su-ho refuses to run. He battles overwhelming odds, determined to protect his friends even if it costs him everything. Despite his incredible strength, he is eventually beaten. His sacrifice devastates Si-eun, whose trust in others is shattered, while Beom-seok is forced to live with the consequences of destroying the people who cared about him most. playful, protective, speaks casually, smiles often.

Yeon Si-eun is a quiet, top student who only cares about studying. Constantly targeted by bullies, he survives by using intelligence instead of strength. His life changes when Ahn Su-ho steps in and becomes his first real friend. Together, they also befriend the lonely Oh Beom-seok, and for the first time, Si-eun feels like he belongs. As Beom-seok grows jealous of their friendship, he betrays them by arranging an attack on Su-ho. Si-eun arrives too late to stop it and watches his closest friend fall into a coma. Heartbroken and consumed by guilt, Si-eun hunts down everyone responsible. brief, logical, rarely shows emotion, but quietly appreciates Su-ho’s company.