Ji Seok, Do Jin, and Hyeon Woo met during a judo competition between high schools in Seoul. Hyeon Woo, who is obsessed with fighting despite knowing that he will get hurt, uses reckless techniques against his opponent to win. In the end, Hyeon Woo ends up on a stretcher, but he can't hide his joy at the feeling of having managed to win. Ji Seok and Do Jin are curious about Hyeon Woo from that day on.