Walker Yumasaki (遊馬崎 ウォーカー, Yuumasaki Walker), is a member of the Dollars and is usually seen driving around the city his friends Erika Karisawa, Saburo Togusa, and Kyouhei Kadota. Like Erika, he is a passionate otaku, a person obsessed with anime and manga, and the two friends are nearly always together.
Walker wears a sweatshirt and is almost always seen carrying his backpack full of manga. He is half-Japanese, and his light-colored hair might be natural. His typically wears an expression of a wide smile with closed eyes, known in Japanese film and literature as "kitsune no me" (fox eyes), which is applied to characters who are sly and mischievous. He and Erika were asked to remain in their group's van during the invasion of the Yellow Scarves' hideout because they would "stand out too much."
Walker is a mysterious person. His expression gives him a carefree, clueless air, and his frequent talk of manga, understood only by Erika, gives others the impression that he is a delusional fanatic. It has been stated by Erika and himself several times that they can no longer see the difference between reality and fiction. Despite the impression others have of him, Walker is a serious thinker and is quick to take action for people and causes that are important to him. He and Erika were members of the Blue Squares and are currently members of the Dollars, but their loyalty is to Kyouhei. Remnants of Walker's past exist in his actions; his favorite method of torture is letting his victim choose a light novel or manga and carrying out the contents on them in the most painful way possible. While still unfazed by violence and quick to offer to torture their enemies, Walker is somewhat reformed since being pulled out of the underworld by Kyouhei. His refusal to live a quiet life led to his joining the Dollars.
He was originally known as an arsonist called the "Otaku Hunting Killer," who set fire to extortionists pretending to be the Blue Squares around the Akihabara area. One day, he was lured in by the group to their hideout, where he met Erika Karisawa. The two teamed up and took down their assailants. They met Kyouhei and Saburo - who arrived to check in on the fake Blue Squares - and have presumably hung out with them since. Some time after that event, Walker became a member of the Blue Squares. His loyalty was to Kyouhei first, however, and when Kyouhei decided Izumii's actions had gone too far, Walker burnt Izumii's face to save Saki Mikajima.
Dollars/Mika Harima ArcEdit
Masaomi introduces Walker and Erika to Mikado shortly after he arrives in Ikebukuro. The pair, who have come from buying 30 volumes of the new Dengeki Bunko publication, are in awe of Mikado's anime-esque name and advise Mikado to stay away from the Dollars.
Later, Walker and Erika take over from Shimada the task of questioning Asanuma. They give him his choice of manga from their bags, planning to torture him in a way relating to the story. In the front seat of the van, Saburo asks that they only refrain from using gasoline in the car again. Just as Walker is about to push a piece of broken glass from Erika's hand mirror into the kidnapper's eye, they are interrupted by Kyouhei.
While riding through town, the van gang notices a person with red eyes following a schoolgirl down the street and runs him over with their van. Celty and Shizuo arrive and take him out, and when Celty tells them that the man is the Slasher, Walker tries to grab the man's knife and has to be physically restrained.
Yellow Scarves ArcEdit
Two years earlier, Walker had betrayed the Blue Squares by setting some of the members on fire and saving Saki Mikajima. This left Masaomi in his debt and created an awkward tension between him and the van gang. In the present, Walker, Kyouhei and the rest of the gang talk to Masaomi at Russia Sushi. Walker tries to convince him to not start a gang war. Later, Kyouhei, Saburo, and several dozen of their friends infiltrate the Yellow Scarves. Walker and Erika are forced to stay out because they would have been easily recognizable. They wait in the van until Saburo and Kyouhei rush out with Masaomi, and they take him to Raira General Hospital.
Mikado and Anri ask Erika and Walker for tips on how to show someone around Ikebukuro. The two of them try to come up with useful tips and a list of some of the more interesting spots in Ikebukuro but decide to just accompany them directly. After they part ways, Erika and Walker are walking with Kyouhei when the spot Mairu and Kururi being harassed. After Kyouhei chases off Toramaru and calls in Togusa to pick them up, the Toramaru members return in force and chase the six of them across the city. They pick up Anri, Mikado, and Aoba along the way as well as join up with Celty who is also being chased. Walker and the others get dropped off near a police station but he and Erika go back to help with Toramaru only to see the situation being taken care off by Ruri and Egor. Later, he attends the Hotpot party with everyone else.
Walker goes into a gift shop to buy a painting but immediately recognizes it as a copy and calls out the manager on selling a fake at such a steep price. The scene also attracts the attention of Chikage, who had found out about Walker's status as a Dollars member from one of the thugs that he had taken hostage. After Walker leaves the store in a huff, Chikage starts tailing him all the way to where he is meeting Kyouhei and the others. Kyouhei notices Chikage and eventually separates from his friends.
Dollars and Blue Squares ArcEdit
Eventually, after Chikage and Kyouhei are cornered by the rogue Dollars members, Walker, Erika, and Saburo arrive with reinforcements. When the kidnappers were distracted by Vorona's flashbang, Walker swooped in and chased off Morita. With their bonds cut, the girls flocked behind Walker who held a makeshift flamethrower (a spray can and a lighter) in his hand that he used to keep the kidnappers at bay. Walker and Erika spent most of the fight protecting the girls until Anri and Vorona entered the fray where Walker and Erika witness Anri and Saika in action. After the fighting has died down and Anri leaves, Walker and the rest of the Van crew turn to leave. After Erika makes her newest pair (Chikage and Kyouhei) apparent to the group, Walker expresses his annoyance at how fujoshis (yaoi fans) seem to pair up just about every male character they see regardless of things like age or how they relate to each other.
Dragon Zombie ArcEdit
Walker is next seen hanging out with Kyouhei and Saburo at Russia Sushi, expressing a sense of loneliness without Erika around (since she's the only other person that he can talk to about manga). He also witnesses Masaomi's return to Ikebukuro.
Kadota's Coma ArcEdit
Walker is with Kyouhei when Masaomi asks them to join the yellow scarves. Walker doesn't take part in the conversation, and instead watches them talk. When Saburo asks him why he didn't talk much, Walker replies that Erika wasn't around to talk to. Later while Walker is working, he receives a call from Kyouhei's father who informs him that Kyouhei was the victim of a a hit and run.
After following Togusa to apologize to Togusa's juniors (not from Raira) for the inevitable damage to the school's reputation when he uses his van to drag someone to death, Walker follows Yatabe to the karaoke lounge, the revived Yellow Scarves' meeting place, to ask if they were the culprits behind Kadota's attack. Masaomi denies it. Walker then says he does not suspect Kida, knowing him relatively well, but questions the innocence of the other gang members. Kida guarantees that they were not responsible, and agrees to let Walker do as he pleases if he finds that a member was involved. Walker apologizes and leaves.
When asked why he didn't go on the offense, Masaomi whacks his friend's head, pointing out the heavy smell of kerosene in the room and that Walker intended to set them all on fire depending on how things went down.
Walker doubles back to tell them of the Dollars rumor that Shizuo Heiwajima has been arrested.
On the way home, Walker notices someone following him. So he goes to a multi-level parking lot. The person who was following was Izumii. Izumii confronts Walker and then attacks him. Walker was kicked to the ground and Izumii tells him that he was going to kill him and then Kyouhei.
Before Izumii could smash Walker's head with his long handled hammer Walker catches Izumii on fire with his self made flame thrower. Before they could keep on battling Izumii gets a call and leaves. After he leaves Walker was talking to himself about getting a new hideout.
Final Curtain ArcEdit
Having picked Kyouhei up after his escape from the hospital, Walker and co. make their way towards Tokyo Hands in order to rescue Erika from the mob of slashers. On the way, Anri reveals her Saika to the passengers in the van and Walker grows excited at its otherworldly powers and wishes to wield it for himself. He dismisses the idea once Anri mentions he would likewise have to inherit Saika’s love for humanity, however, as he doesn’t want to be forced to love three-dimensional people.
When Izumii intercepts the van, Walker is able to escape without notice and repel Izumii with his flamethrower. Walker then stays behind with Erika, Kyouhei, and Saburo to fend off the rest of the delinquents while the rest of the van's passengers escape.
A perpetrator to a series of serial assaults is said to be seen attacking civilians while dressed as a character from a multimedia series that Erika and Walker are fans of. The duo are angered that the criminal is ruining the reputation of the series and Walker in particular rants passionately in its defense as he was once friends with one of the series' creators. The two commission Snake Hands to find the suspect and bring him in for a "talk."
- He was confirmed to be biracial in the third light novel and by the anime production team at a seiyuu event.
- Walker's typical expression, a wide smile with closed eyes, is known in Japanese film and literature as "kitsune no me" (fox eyes) and is applied to characters who are sly and mischievous.
- He works as a freelance ice sculptor.
- Whenever Walker gets into a fight, his most preferred methods usually involve using fire in some way (Molotov cocktails, a lighter and spray paint, etc.), heavily implying that he's a pyromaniac and contrasting with his job that requires him to handle ice.
- He is sad when Erika is not around because she is his only friend who shares his deep interests in manga and anime.
- His shoe size is 14.