Story
he touched his friends and they all died
background
Ten years have passed since the Great Tokyo Earthquake which sank over 70 percent of Tokyo into the ocean. A publicly-operated prison--in which the inmates are running attractions to the tourists, has been built in Tokyo for the sake of reviving the dead city. The prison is called Deadman Wonderland.
the beginning
One day, Ganta Igarashi, a survivor of the said earthquake; loses all of his classmates when a strange man covered with blood appears outside the building and slaughters them all. The red man disappears after embedding a crimson diamond in Ganta's chest. As though the shock of losing his friends wasn't enough, Ganta is convicted to be the mass-murderer. He is then sent into Deadman Wonderland to receive a Death sentence.
When the chief warden, Makina, is giving the just-in prisoners some brief explanation regarding Deadman Wonderland, Ganta was hit by an earlier prisoner with a cart--whose name is Takami Yoh, and soon will become his friend--and Makina accuses that guy for stealing; and slices him on the spot.
Ganta finds it totally unfair and twisted, and he keeps telling himself that he just wants to die. That is when a mysterious girl with white hair and red eyes suddenly jumps in his cell by destroying the window. Out of nowhere, she tells him that she'll kill him if he wants; and starts attacking him, but he dodges. She then decides not to kill Ganta because she believes Ganta's "I want to die" musing is a lie. She also tells him that she is Shiro, appears to be Ganta's childhood friend back in Tokyo, but Ganta can barely remember.
Ganta's meeting with Shiro makes him realize that he doesn't want to die yet. He needs to prove that he's innocence and find the real murderer of his friends and get him executed. He is determined to survive in the twisted, stressful and challenging life in Deadman Wonderland no matter what.