Lee Myung-jun, the Vice-Chairman of Hyundo Group, tragically lost his daughter to a group of school bullies. Seeking vengeance, he adopts Yoon Karma, a psychopathic North Korean defector. Yoon Karma is a sadistic human weapon, created through drug experiments in North Korea. After killing everyone in the research lab, she escaped to South Korea on her own. Having just been released from a young offenders' institution, Yoon Karma sets out to hunt down the bullies at school, driven by the desire to avenge her new father and satisfy her own sadistic pleasures.