Yahiro Mizuchi

Yahiro Mizuchi（みずち やひろ), is one of the three main protagonists of Durarara!!'s second part, Durarara!! SH.

Background
As an infant, Yahiro was abandoned at a hot spring village in the mountains of Akita, far from human society. He was left at the entrance at certain inn, where he was taken in by the owner, whose daughter & her husband adopted and blessed with the same degree of love as any other child and an environment twice as wealthy. Though there were also those who were jealous that he, despite lack of blood relations, was raised by a powerful family of the village.

When he entered elementary school, six year old Yahiro demonstrated his "ability" when he was picked on by his seniors, five infamous delinquents, though he had no idea why. Angered by his lack of response, one ruffian punched him and grabbed his collar, in which case Yahiro finally replied in the form of ripping off the ruffian's ear, a headbutt to the nose, & mercilessly breaking his fingers while kicking him in the face. Though he was acting out of purely fearful instincts, this event caused him to become a feared entity in the village. Despite the declining population of the village, there were many problematic children. There were older boys who intended to teach this brazen child a lesson, under the name of avenging their friend. This act only served to them the same fate, albeit much more horrific & bloody. As a result, no one else in the village attacked him. Though when he got older, rumors from the defeated delinquents reached people from the surrounding regions, who started to pick fights with him.

This was what caused others to started calling him a monster and because the fights never stopped coming, once a group of delinquents even attempted to set fire to the inn, he decided to train himself in order to repel the incomprehensible terrors that came down on him, though this made gaining friends impossible. Despite this, the police recognized his violent behavior as rightful self-defence and managed to spare him from having to enter a boys' home. While he appreciates his family's kindness & refusal to abandon him, it only made him feel lonelier and became nihilistic when he was fifteen.

On a day nearing the end of summer, a tourist from Tokyo came to the village. On the way back from watching the Oomagari Fireworks Festival, the guest stayed at the hot spring inn, where he curiously watches the climax of Yahiro's fight with some delinquents. After it ends, he smiled to Yahiro, who stood in the center of the fallen, bloody delinquents, saying “It’s nice for kids to have so much energy”. Shocked, (because other tourists would usually be scared and never genuinely smile) Yahiro listens as the seemingly amoral man praises him for following his human instincts and when asked if he thinks he was a monster, the tourist replies:

“It’s true you seem to be good at fighting, but doesn’t that just make you a human who can fight well...? There are people more inhuman than you in the world, and even supernatural creatures exist, after all.”

Realizing the tourist was not lying, Yahiro felt himself a strong waver at being called “human” in his current situation and asked him where he came. The tourist answers ‘Ikebukuro.’ and leaves. An interested Yahiro begins researching Ikebukuro on his smartphone, eventually finding sharply-taken photos & videos of oddities like the Headless Rider, "Ikebukuro's God of Destruction", several color gangs & The Slasher. Grasping this info as time passed, he obsessively digs in for more to know, feeling a new world had opened up to him.

Declaring these monstrosities to be terrifying, Yahiro's curiosity surpasses his fear and deems his smartphone to be insufficient to satisfy that. He then, for the first time, "selfishly" request his parents to let him enter a school in Ikebukuro to learn more. While hesitant at first, his grandmother's final say, that he's grown his own old enough to take care of himself, convinces them to accept his request.

The cowardly monster resolved to enter Ikebukuro to face the world he had given up on once more and to meet the true monsters he knew not of yet, at that point, the city of the strange welcomed a new breeze.

Durarara!! SH:
As the story begins, Yahiro is riding on the Yamanote line, reminiscing about his past, when he overhears some passengers beside him talk about the "Headless Rider." This slowly begins to interest him. As he gets off the train, he is greeted by Saburo's brother, Jiro, who then begins to explain that Saburo has seemed more human, since "chasing after" Ruri Hijiribe. He then goes on the explain about Kadota, and the city, while Yahiro listens on.

Later on, he is listening to the class introductions, when he notices two people: Kotonami Kuon, and Tatsugami Himeka. After watching Kotonami's introduction, he thinks to himself that his green hair is a trend in Tokyo, but quickly dismisses it. When Himeka's turn comes, he notices that she's really pretty. As his turn name is announced, he goes through the standard introduction, but is quickly perplexed, when asked why he moved from Akita, to Ikebukuro (wanting to keep the reason a secret, because he was afraid he would not make any friends if they knew his past). He then replies that he wishes to see the Headless Rider, and begins to get worried once laughter starts spawning around the classroom, but quickly becomes relieved once her hears the others start talking about it.

As class ends,  he is gazing out of the window, looking at the city, when he feels a strange feeling inside of him, and begins to smile. Suddenly, Himeka, asks him if the answer he gave was a joke, or if he was being serious. After a small exchange, Himeka bluntly tells him not to look for it, that that's a warning. Getting scared, Yahiro instinctively grabs Himeka's collar, and pulls her back, choking her, and asking her what she meant. Realizing what he did, he let's go, and begins to apologize. Himeka stares at him in disbelief, but then apologizes while leaving the room, stating that she honestly meant for it to be a warning.

As he is leaving the school, he ponders whether he should apologize to Himeka once again, but is quickly cut off by Kuon, who calls his name. Kuon then goes on to talk about the clubs at school, and other random things, before telling him to call him by his first name, "Kuon," since he did the same with Yahiro. The two then leave, and arrive at the dojo, where Mairu is training. Kuon and Mairu begin talking, and Yahiro gets dragged into the conversation. This is also the first time that Yahiro hears Aoba being mentioned. Immediately after the Aoba conversation, Akane Awakusu walks over, and joins in, stating that the Headless Rider would not kidnap anyone. When asked by Yahiro how she knows such a fact, she remains quiet.

Appearance
Yahiro appears to be around 14-15 years of age. Illustrations shows he has either gold eyes with brown hair or ice-blue eyes with light blue hair (though Tom has claimed he has black hair). He wears a black, button-up blazer, with a white undershirt, complete with a black tie. His bangs are swept out of his eyes, framing both sides of his face. His hair is a little messy, standing up a little bit on top.

Trivia

 * On the official illustration spread for Durarara!! SH, on Dengeki Bunko's site, it shows him talking to his friend, Kotonami Kuon, with a curious look on his face. Beside it, however, he is shown speaking to someone (who, from behind, has a striking resemblance to Mikado Ryūgamine), with a mischeavious smirk on his face. This could indicate he has a personality like Aoba Kuronuma, or Mikado.