OVA
Description
Walker Yumasaki is a half-Japanese member of the Dollars, frequently seen with Erika Karisawa, Saburo Togusa, and Kyohei Kadota. He is recognized by his light-colored hair and perpetually closed eyes, lending him a sly, "kitsune no me" (fox-like) expression. His typical attire includes hooded sweatshirts, jeans, sneakers, and a black backpack filled with manga.

Formerly active in Akihabara as the arsonist "Otaku Hunting Killer," he targeted extortionists posing as the Blue Squares gang. Lured to a Blue Squares hideout, he met Erika Karisawa; together they defeated their captors and joined Kyohei Kadota's group. Walker later became an official Blue Squares member but prioritized loyalty to Kadota. His most significant betrayal involved saving Saki Mikajima by setting fire to Blue Squares members, leaving Masaomi Kida indebted to him.

Personality-wise, Walker presents as a carefree, manga-obsessed otaku with encyclopedic knowledge of anime, games, and light novels. He frequently engages Erika in deep discussions about fictional worlds, often excluding others. This cheerful facade masks a capacity for calculated violence. He employs torture methods inspired by fiction, offering victims a choice of manga or light novel before painfully reenacting its content. His preferred weapon is a makeshift flamethrower crafted from a spray can and lighter, reflecting his arsonist past. Despite Kadota guiding him away from the underworld, he remains unfazed by violence when protecting allies.

Walker experiences moments of introspection, expressing loneliness when separated from Erika, his primary confidant for otaku discourse. His commitment to Kadota deepens, notably when he investigates Kadota's hit-and-run accident. Prepared with kerosene to burn the Yellow Scarves if implicated, he later confronts his former Blue Squares leader, Izumii, using his flamethrower in self-defense.

In later events, Walker assists Mikado Ryugamine and Anri Sonohara in navigating Ikebukuro and participates in group efforts against threats like the Toramaru biker gang and Saika-controlled slashers. He demonstrates protectiveness, using his flamethrower to repel attackers during the Final Curtain Arc. He also displays ethical boundaries regarding fiction, commissioning Snake Hands to apprehend a criminal misrepresenting a beloved multimedia series, emphasizing his disdain for real-world misuse of artistic expression.

Walker's surname, Yumasaki, combines the characters for "play," "horse," and "cape/peninsula." He dislikes censorship of expression and claims no food preferences, stating he would eat insects to prepare for transitioning to a "2D world." His hobbies include all fictional media, anime songs, and ice carving.