The Deadman mass prison break was an operation set up by Scar Chain. Its goal was to expose the secrets of Deadman Wonderland to the outside world. These are the existence of Deadmen and the Carnival Corpses. This was supposed to lead to the shutdown of DW and the release of the Deadmen. The operation was a failure because DW still operated afterwards, but was also a success because several Scar Chain members eventually escaped.
In prospect of the prison break, Scar Chain made an agreement with an infiltrator in the DW inspection team. He will distract Tsunenaga Tamaki. Rokuro, the chief of intelligence, also made a data chip that contains all the information about DW that is needed to shut the prison down. That is the evidence that Deadmen exist and the many illegal acts Tamaki commits. That disk will be handed over to the inspection team and he will expose it to the world.
The actual operation started in the week of the annual DW inspection. Then, there will be less guards and the show will be put on hold (including the Carnival Corpse). Before the actual operation itself, they activated emergency alarms in several positions, causing major confusion. Then, Scar Chain will begin to move into two groups (Karako, Ganta and the other Scar Chain members and Nagi and Rokuro).
Karako and her group move towards an elevator that can bring them in safety and where they will hand the data chip to the inspection team. To get to the elevator, they managed had to go through a restricted area. They managed to get access, but were unable to prevent the coming of a Necro Macro. The group was threatened to be killed, but Karako sacrificed herself by fighting the Necro Macro alone. She handed the chip over to Ganta. Karako won, but fell from the hanger and was unable to go through. Ganta's group eventually got to the elevator, that wasn't moving yet.Meanwhile, Nagi and Rokuro broke in the control room and defeated the guards by using their Branch of Sin. The goal of this action was to activate the elevator, that would bring the other group in safety. As Nagi was about to activate it, Hibana Daida showed up and attacked him. She cancelled Nagi's Branch of Sin with her Worm Eater and explains why. It's then that Nagi realizes that Rokuro manipulated the footage of Ganta attacking Genkaku. Rokuro reveals himself to be on the Undertaker's side. During the fight between Nagi and Hibana, Nagi was able to defeat Hibana and punch Rokuro. He then activated the elevator.
The remaining Scar Chain members then got on the elevator, making small talk on the way. They arrived at a storage area, but are awaited by the Undertakers, led by Genkaku, who immediately starts firing. Fujiyoshi and another unnamed member are hit and die. Some members summon their Branch of Sin, but they are all cancelled by the Undertakers' Worm Eater. Miya is beheaded and Kazu flees into a room, but is burned to death. The Undertakers clash with Scar Chain.
Meanwhile, Nagi has collapsed and Rokuro talks to Nagi saying that the Undertakers are after the others too and that they only have a 1,2% chance of survival. Nagi says that's enough and still believes in the success of the operation. However, Rokuro explains that it's his job to make those chances zero, and implies that the data chip is actually a bomb. When Rokuro isn't looking, Nagi takes out his radio transmitter and contacts Scar Chain's base's computer. There, Shiro hears Nagi's voice who says that the data chip is a bomb and that somebody has to prevent it to kill the other Scar Chain members. Shiro leaves and searches for Ganta and the rest.Back to Scar Chain, is almost everybody killed, except for Ganta and some other unnamed members. When Genkaku is about to kill Ganta, Mōzuri comes up and tells him it's time to retreat. Scar Chain regroups and gets ready to escape, but Shiro suddenly appears, takes Ganta's data chip and throws it in the fire, where it violently explodes.
Scar Chain had no choice to retreat after that, and they gathered back in Scar Chain's headquarters. There, they met up with Karako again. They pitied themselves and wanted to give up, but Karako pursued them to go on with the plan.
At the Scar Chain hideout, Rokuro appears, furious and demanding to know how they could have figured out he planted a bomb in the data chip. Shocked at this revelation, the Scar Chain members have no time to react before Undertakers swarm in, joined by the 2nd squad leaders Mōzuri Gazuchi and Shinagawa Dōkoku. Rokuro plans to have them kill each member of Scar Chain individually, starting with Ganta, but seconds before, Senji Kiyomasa appears and kills them both effortlessly. Everyone begins to attack the Undertakers, Senji revealing that the way to defeat their Worm Eater weaponry is to break the sound barrier, such as with his Invisible Black.
After defeating the Undertakers and retraining Rokuro, Karako manages to gain information on a secure route out of Deadman Wonderland from him. With everyone carrying a copy of the data chip, they plan to try a second escape. Though they ask Senji to join them, he refuses, saying the outside world is no different than the one in prison. Ganta, asking how they could simply escape and leave Nagi behind, storms off, following Senji in the hopes he would train him to break the sound barrier. Secretly, Karako plans to dress an Undertaker and infiltrate their ranks to rescue Nagi.
As the Scar Chains members spread out down the secured path and Ganta trains with Senji, Genkaku reveals that he has captured both Karako and Shiro, threatening that his men will rape and kill them if the Scar Chain members do not reveal themselves. Ganta leaves to rescue Shiro and the Scar Chain members all decide to abandon their escape to save Karako.
Ganta confronts Shiro after when she threw the data chip into the fire. It is later revealed that this was a bomb.
(Note: In the anime, only Ganta returns to rescue Shiro and Karako. The events detailed here are correspondent to the manga.) After Genkaku's challenge, Ganta arrives moments before the Undertakers can have their way with Shiro and Karako. He is quickly joined by the rest of Scar Chain, all brandishing heavy weapons to compensate for their Branch of Sin being disabled. As the two groups begin battle, it appears Scar Chain has the upper hand, despite Hibana joining the Undertaker soldiers. Deducing that Nagi must be behind two large doors in the room, Wakabayashi fires a rocket, blowing them apart. Seeing him inside, Karako rushes to Nagi, only for him to tell her to leave him before he kills her. Yamazaki goes to great him, but is nearly strangled to death before Genkaku shoots his limbs off.
Nagi begins a rampage, killing friend and foe alike. Delighted, Genkaku joins him, randomly firing his guitar at anyone and everything. Hibana begins to panic, as one of Genkaku's stray shots hits her arm. She escapes before anything else can happen. Before Nagi can hurt Shiro, Ganta steps in front of him, taking the full force of numerous attacks against him. Ganta's resolve and Karako's bell eventually snap Nagi out of his madness, only for Genkaku to stab a sword through Karako's chest and shoot a large hole through Nagi's stomach. Enraged, Ganta fires his Ganbaru Gun, breaking Genkaku's Worm Eater pendant. Trying to flee, he is stopped by Nagi, who says he will be his guide to hell. Smiling, Genkaku takes the full force of the attack, being blasted through the ceiling and out of the building.
As Nagi lays dying, he gives Ganta his last piece of candy, as it as nearly time for him to succumb to the poison. Seeing the large opening in the side of Deadman Wonderland, Scar Chain leaves for the outside, successfully managing to hand off a data chip to the member of the inspection committee they'd contacted. Ganta stays, however, feeling the need to look after his friends. For his aiding Scar Chain in their breakout, he is sent to solitary confinement for for one week for withholding information.
- Nagi Kengamine
- Karako Koshio
- Ganta Igarashi
- Other unnamed Scar Chain members
- Tsunenaga Tamaki
- Rokuro Bundō