It appeared to be an ordinary day for Ganta Igarashi and his classmates, who were getting ready for a school field trip to a specific prison amusement park named Deadman Wonderland, where inmates perform hazardous stunts for the spectators' entertainment. However, Ganta's life is rapidly upended when his entire class is slaughtered by an enigmatic figure dressed in red. Wrongfully accused of the massacre and condemned to death, Ganta is transferred to the very facility he had intended to visit. Yet, Ganta's ordeal has only just commenced. The young protagonist is plunged into a realm of cruel prisoners and mysterious abilities, living in perpetual dread of the lethal collar around his neck, which can only be deactivated by winning the prison's deadly games. Ganta must risk his life to endure in this merciless environment, where distinguishing allies from enemies is not always straightforward, all while attempting to locate the mysterious "Red Man" and exonerate himself in Deadman Wonderland.