Ten years ago, a legendary fighter named Choi Gi-dong and a timid straight-A student named Park Young-joon leave for a high school field trip to Gyeongju city. But during their journey, fate befalls on them as they experience an unforgettable incident that would change the course of their lives. One night during a school gala, Gi-dong leads his entire school to a huge brawl against a local gang while Young-joon chickens out and stays behind at the party by himself. The streets turn out to be a battlefield with blood gushing, heads bashing and bones breaking, but the gruesome fight nonetheless becomes history in the making. Gi-dong becomes admired for his brevity, while Young-joon gets ostracized for his fear.