nameless stranger.
once upon a white christmas; the boy and “allen”
Before Allen met Mana, he was just a lonely nameless brown-haired boy who was abandoned by his own parents. He was born with a strange left arm—it was blood-red and there were wrinkles all over it, with a cross embedded on the back of his left hand, and he could barely move it. The boy didn’t know his real name nor birthday, that’s why everyone referred to him as Red or Red Hand. He was sold to a circus and performed odd jobs there. With everyone disgusted at him and nobody cared to give him some love, the boy believed that he didn’t need any friends. He was under an environtment that shaped him to be an introverted sour-faced boy. He was constantly being bullied by Cosimo, the clown from the said circus, but he couldn't do anything because nobody would believe him.
Then came the fateful day, when he was about seven years old. He met a dog in the circus—it belonged to a travelling clown who temporarily worked for that circus. The dog wanted to play ball with Red, and it kept following him. Red, who never had friends, must have felt very happy and wanted to play with the dog, too. However, he realized that the dog’s owner would leave and take it away.
Once, Red watched the clown and the dog’s performance. He, who never knew about love, was jealous at the dog and his owner—how they were loved by the audience when they performed, and how strong their chemistry was. After the performance, the dog came to Red, who was crying. Little Red didn’t know what to do, between wanting to “love” and feeling envious. He ended up kicking the dog. He regretted it afterwards, but he didn’t know what to do and chose to run away.
A few days later, Red, who had been feeling guilty, approached the dog and pet him. To his surprise, the dog licked his arm. The red left arm, which everyone is disgusted at. For the first time in his life, Red felt love—that’s why he was very happy. He felt that it had forgiven him. Red thought that he would play with the dog the following day... unfortunately, that never happened.
The following day, he found out that the first creature that gave him love was dead.
Its body was covered in bruises—Red knew that it was Cosimo’s doing, just because the dog’s owner was a better clown than he was. Red tried to hide his feelings, but after he talked to the owner—Mana Walker—while watching him burying the dog, he finally cried.
Red: “This guy... What's his name? I pet him yesterday, and he licked me. His tongue was warm. So I thought, today I’d...... Why? That's all it was, but why am I crying?” Mana: “I see. You were Allen’s friend, weren’t you.”
— Red and Mana Walker, D.Gray-man Reverse 3
Red was stunned when he heard the word “friend” , because he never imagined that he would make friends with anyone. He never knew the dog’s name, and wished that he could call its name and play with it. He cried until he fell asleep, and Mana carried him on his back.
Later on, while Mana was giving out the circus flyers, Mana sort of challenged Red to perform in front of the crowd. Red managed to perform a few tricks very well. He felt very happy because the audience was amused. A red-haired priest approached the kid and told him not to get too close with Mana, then disappeared. When Red told Mana about it, the man suddenly ran, trying to find the priest, saying that it could be his lost little brother—the very reason why he travelled.
Sometime later, when the performance was about to begin, Red confronted Cosimo, but Cosimo told everyone that Red killed the dog. Of course, everyone bought it. Red’s patience had reached his limit, and planned to take his revenge to Cosimo, but Mana protected Cosimo and got hit instead.
Red was taken away by the other circus members, and he didn’t see Mana until the following day: Christmas. However, the other circus performers disappeared mysteriously. When Red came to Mana, the man smiled. However, something was wrong.
"Where have you been, Allen?” [...] “Allen is really warm. And, strange? Why have you grown so big? And you don’t have a tail as well.” — Mana Walker, D.Gray-man Reverse 3.
He mistook Red for “Allen”. The dog. Red tried to remind him about his little brother, but Mana was confused. Red felt that Mana had become like that because of him.
“Take me with you Mana. I’ll tell you, what you have forgotten…I'll remember it for you….please. [...] Playing in the snowy night with your dog, then going out to the streets with you yesterday, it was the first time I felt “happiness” together with someone else. So, this time, it's my turn. I will be your Allen.” — Red, D.Gray-man Reverse 3
Before Allen’s flashback in Chapter 166 was shown, I've always thought that Mana gave Allen a name and a birthday intentionally. But it looks like I was wrong all this time—one chapter from the third D.Gray-man novel confirmed that Allen was named “Allen” because Mana mixed him up with the dog, because he lost his mind. And it was most likely Allen who gave himself a birthdate, because “Allen” was reborn on Christmas.
However, he was just Allen before he went on a journey with Cross. Before he left, someone called him Allen Walker for the first time. Allen was shy because he thought he didn't deserve Mana's family name, but Cross said that it suited him. Allen Walker seemed very happy when he inherited the surname.