Leon, an 18 year-old boy who's working and investigating secretly to help the authority catch up the killers and other criminals. On his mission, he did not expect that he would encounter the notorious and mysterious serial killer known as Mr. Pride. Because of this, he thinks that he needs to reveal his Vigilantism to Luckey, a Police Detective and Profiler from Violent Crimes Unit. A group of young people with a different bad experience from their past decided to join a Vigilante organization called "Anti-Predator Squad."