Middle school student Ganta Igarashi witnessed the slaughter of his entire class by the mysterious 'Red Man', and as the only survivor, he was labeled a mass murderer and sentenced to death. Now an inmate at the privately-owned prison and ‘amusement park' known as Deadman Wonderland, Ganta must try to survive in a place where inmates are the main attraction in brutal gladiator-style games. At the same time, he must attempt to uncover the truth behind the ‘Red Man', his mysterious childhood friend Shiro, and why he was the only survivor that bloody day.