Hyunsung Kim

After losing their parents and enduring severe school violence at the hands of Park Min-cheol's gang, Kim Hyunsung falls from the school rooftop at 19, resulting in a vegetative state. Trapped in this condition for over a decade, they vow revenge on their tormentors and the Golden Circle, an organization that ruined their life.

Miraculously, they regress to age 17, just before the violence begins. Armed with knowledge of the future, Kim Hyunsung seeks to dismantle Park Min-cheol's gang and ultimately confront the Golden Circle to reclaim their life.