Ganta Igarashi

Ganta Igarashi (五十嵐 丸太) aka Woodpecker, the main protagonist of the story, is a seemingly harmless, ordinary middle school boy who is framed for the slaughter of his entire class, perpetrated by the mysterious Red Man. Sentenced to 'death' after a phony trial, he is sent to Deadman Wonderland, where he is initially confused and frightened by the brutality of the prison. Shortly after arriving, Ganta discovers he can manipulate his blood and, thus, is deemed a Deadman. Ganta appears to have gained this power from a shard of crimson crystal the Red Man fired into his chest after the massacre at the school. He has feelings for his childhood friend Shiro, ironically the very same Red Man that he's bent on killing out of revenge. When he was out of Deadman Wonderland, he realized that fact and confronted her about it.

Prison arc
[Nagano school massacre] Ganta first meets and befriends Shiro when he was agitated by the fact that he was sentenced on death row, saying that he wanted to die (which he denies after Shiro comforted him). After picking a fight with other prisoners, leaving Shiro unconscious, the ball statue on top of a building begins to fall on top of them. To his fury of will to live, Ganta encounters his Deadman powers. The next day, he meets Azami Midō, she tells Ganta about Cast Points. Knowing that he'll die the next day, Ganta decides that he can only survive if he won the Dog race and receive 100,000 cast points to buy a candy. During the Dog Race, Ganta was constantly disturbed by Shiro and therefore, lagging behind. But soon after, He finds out that Shiro had meant to protect him. Ganta then shows mercy and saves Shiro, making there no winner of the Dog Race.

Deadman arc
As a Deadman, Ganta is forced to fight and survive in the Carnival Corpse under the moniker Woodpecker while trying to locate the Red Man, who apparently is held captive in Deadman Wonderland. Ganta's power, dubbed the Ganta Gun by Senji, allows Ganta to gather variable quantities of blood in the palm of his hand and then shoot them at high speed, as if they were bullets. While advantageous as a long-range attack, due to Ganta's small stature, this also puts him at risk of experiencing symptoms of excessive blood loss.

Scar Chain arc
Ganta participated in Scar Chain's attempt to escape from DW, and helped several members escape along with video and audio evidence of the atrocities being committed below the prison. Ganta, however, chose to remain behind to continue his search for the Red Man. Shortly after these events, Ganta's power began to change, evident by a strange tattoo-like mark radiating out from the crystal in his chest. His Ganta Gun now emits a much more powerful blast than before, though it is much less controllable and causes him physical pain.

Abilities
Enhanced Endurance: It has been noted by Shiro that no matter how much damage he has taken Ganta always gets back up. His endurance is so great that he can take numerous punches and 'Owl's Eyeball' attacks from Nagi Kengamine and still stay standing.

Branch of Sin: As a Deadman, Ganta possesses a Branch of Sin. This allows him to freely control his blood. He usually bites his thumb to forcedly bring his blood out. His ability came from the Red Man who forced a Red Diamond into his chest after all of his friends were murdered

Branch of Sin: Ganta Gun (丸太・ガン, Ganta Gan): Ganta collectes his blood in his right hand and shoots it away (simillar to a bullet, hence the name Gun). He first uses this ability at the first day he was in DW. A boulder was thrown down with the intent to kill him and Ganta fires his Ganta Gun and crushes the boulder. He has trained his Ganta Gun to be faster and stronger with the help of Crow. The bullet of blood can also reflect against other objects, changing the course of the bullet.

Supersonic Ganta Gun: During his training with Senji, Ganta developed a new kind of Ganta Gun. This time, he makes the blood bullet smaller and slimmer. That way, the bullet is way faster and can be fired multiple times after each other. This also reduces the chances of anemia, because Ganta uses less blood that usually. Whereas the regular Ganta Gun is like shotgun, the Supersonic Ganta Gun fires like a submachine gun.

Branch of Sin: Ganbare Gun (頑張る・ガン, Ganbare Gan, lit. "Do your best" Gun): During his fight with Azuma Genkaku, Ganta discovers an improved version of his Ganta Gun. This version has a faster and much more powerful bullet that causes patterned, black lines (shiny red-pink in the anime) to cover his body. However, in the anime only, Shiro is shown to have identical lines on the right-side of her face at the same time as Ganta's appear, this suggests that the Ganbare Gun is linked to Shiro and further suggesting that this BoS is the key Branch to open the Mother Goose System. This Branch of Sin is the only one that has not yet been copied by Toto.

Trivia

 * Ganta's Branch of Sin, Ganta Gun, is the only one known to evolve over time.
 * Ganta_cellphone.png's name can also be read as Maruta, which means "round, cut log". This expresses itself in Ganta's mark, that has the form of a round, cut log with a leaf on it. Apparently, he marks a lot of his stuff with this mark, but it has only been seen on his cellphone in the first chapter and episode.