Shiro

Shiro is a childhood-friend of Ganta and the original Deadman - The Wretched Egg.

Personality
Shiro is a bubbly, happy girl that seems to be a klutz. She also has a lot of energy (most likely from the fact she eats nothing but sweets), although her mind cannot understand much. While she doesn't fully understand Deadman Wonderland, she knows how to help Ganta and only wants his happiness- even to the point of killing him when he asked. She is incredibly strong, however dense she is, and uses her strength to help Ganta as much as possible after a childhood incident between them. During the dog race show, she's seemigly oblivious to the dangers of the game and occasionaly gets in the way of Ganta's progression (or survial) only to be later realised by Ganta that she was discreetly taking Ganta's blows for him.

History
Before the birth of the Wretched Egg, Ganta and Shiro played quite often, sharing a common admiration of Ace Man, a Megaman-like cartoon hero. Shiro was a test-subject of Ganta's mother, so they saw each other often. She got along well, but one time, when Shiro was in grave pain because of the constant injections, they once bickered so violently that Ganta took his toys and ran away from the hospital. Soon after, he came face-to-face with a rabid, vile dog. Ganta dropped to his knees in fear and called for Ace Man to save him. Suddenly, Shiro appeared in between Ganta and the dog, saving his life. After this, Ganta and Shiro were even more close. She was used in nanomachine expirements that led to the creation of the Wreched Egg and Nameless Worm-Nanomachines she seems to be able to produce. As shown her body has been ripped apart several times possibly when her limbs were removed multiple times to create the Chorus Blocks.

Wretched Egg
Shiro's split personality the Wretched Egg (レチッド エグ, Rechiddo Egu), also known as The Red Man (赤い男, Akai Otoko) by Ganta. The Wretched Egg was created by Hagire Rinichirō and Ganta's mother, Sorae Igarashi. The Red Man is the cause of the Great Tokyo Earthquake ten years ago and she is also responsible for the Nagano school massacre. The only way to keep her under control, is the Mother Goose System. Her moniker as the Red Man is due to the full body-restraint suit (which was designed as a limiter to her power) which gives her a decidedly masculine appearance. Out of twisted sense of irony, the Wretched Egg applied her own aesthetics to the body suit (such as the cape and color scheme) so that it would resemble Ace Man, Ganta's childhood hero.

The Wretched Egg is the opposite of Shiro. She is sadistic, appears to value solitude over companionship and doesn't enjoy sweets (whereas Shiro adores it). The most obvious difference is that Shiro is naïve and sweet while the Red Man is vicious, merciless and cruel. The only thing that is consistent between the two is their affection for Ganta (though the Wretched Egg's feelings for him are much more warped when compared to the innocent love Shiro harbors for him). However, it is implied that the Wretched Egg feels some remorse or sadness for her actions. It is revealed that it was due the constant experimentations and the harvesting of her flesh that helped further derang the psychotic persona. It also appears that Shiro and the Wretched Egg are gradually beginning to merge back into a singular personality.

Abilities
Branch of Sin (Shiro): As Shiro, she has shown minimal control of her Branch of Sin and has been able to use it in combat only once. She first discovered her powers when Ganta and Senji were discussing their Branches of Sin. She used it to fight for the first time in Ganta's battle with Shishito Madoka, where she saved Ganta when he was about to get killed.

Branch of Sin (Wretched Egg): As the Wretched Egg, her powers are unmatched even by the strongest of opponents while her powers were restrained by the Mother Goose System. She has been shown to massacre dozens of people by creating a whip of blood that can destroy parts of the body instantly. Her Branch of Sin also resembles a hurricane. While unrestrained, she was powerful enough to cause the Great Tokyo Earthquake that submerged a large area of Tokyo. Its possible her power can spread infinitely and be expressed in multiple forms.

Trivia

 * Shiro's name means white in Japanese.