As a meek high school student, Heo Jeong-woo is used to incessant bullying. No different from his middle school, all sorts of violent people and dangerous cliques prey on the weak. However, a sudden shift in power comes with a new transfer student, Han Bora. Unbothered by the remarks about an unsightly birthmark on her leg, Bora assaults her would-be bullies with shocking force and cruelty, requesting one thing: the identities of those who know a girl named Han Sena. Jeong-woo attended the same middle school as Sena, so he remembers her story—she was nearly killed by bullies and has disappeared since. Desperate to escape his daily hell, Jeong-woo gives up the names of the four students who terrorized Sena. But he must be careful not to stand in Bora's way, as she is unpredictable and incredibly brutal, and all she wants is bloody revenge. [Written by MAL Rewrite]