Back in his high school days, Joon-Seok (Joo Sang-Wook) was bullied by Chang-Sik (Yang Dong-Geun). Because of this, Joon-Seok's high school days were like a nightmare. Now, Joon-Seok finds it difficult to live a normal life due to the bullying. Meanwhile, Chang-Sik, who has forgotten what he did to Jeon-Seok, lives a relatively happy life. He is about to marry Ji-Hee (Lee Tae-Im). Joon-Seok will pay him back for all the misery.