Momoya Agakura belongs to the elite and feared Agakura Clan, a family of underworld mercenaries and hired killers. He ranks seventh in raw combat skill within the family. Standing approximately 230 cm tall with abnormally keen eyesight, Momoya wears distinctive attire: a black-and-white jacket creating an optical illusion of stretched limbs, a black-and-yellow striped shirt, a large belt, sneakers, and a skirt-like black physical restraint cutting off at his shins. Momoya lives for the thrill of combat and killing, exhibiting near-total fearlessness even against supernatural threats. He maintains a lighthearted demeanor, often finding amusement in chaos, and collects autographs from infamous figures like Phantom Solitaire. His eldest sister Majiri criticizes his tactical judgment, urging him to fight smarter. Nearly a decade before present events, Momoya participated with sisters Kana and Majiri in slaughtering a group of small-time terrorists. Child assassin Xiaoyu Lei arrived late and attacked Majiri; Majiri severed Xiaoyu's limbs, promising their return if he joined the clan. Presently, Momoya works under Kuon Higuro, who hired the Agakuras. During a mission framing mediator Lisa Kuraki, Momoya killed an armed "distraction unit" at a station. Later, under Higuro's orders, he decapitated Nishida, an employee of Clarissa (Lisa Kuraki). He assisted in disposing Nishida's corpse in an abandoned building, encountering and dismissing low-level criminals. Momoya later infiltrated hacker Takumi Kuruya's apartment for interrogation. When Misaki Sakimiya intervened, Momoya bisected her torso with his blade; she survived due to vampire larva abilities. During a subsequent confrontation involving Higuro, Momoya, Takumi, and Xiaoyu, Misaki reappeared. Momoya suffered a severe abdominal wound from Misaki's detached crowbar-wielding arm, followed by critical injuries when Xiaoyu pierced his body with extended digits. Grievously injured, Momoya was rescued by sisters Majiri, Kana, and Dahlia, who tracked him to a warehouse. Majiri confronted Xiaoyu and Misaki, crushing Xiaoyu's prosthetic knee and offering Misaki Agakura adoption. Declaring the encounter a draw to prioritize Momoya's medical treatment, Majiri departed with him. Momoya's near-fatal injuries influenced subsequent family decisions. Majiri appointed her brother Yumeji Agakura as Shibuya's new mediator, authorizing him to pursue conflicts related to Higuro's actions and Momoya's injuries. Momoya's key relationships include respect tempered by chastisement from Majiri; service as bodyguard for Kuon Higuro, who later betrayed him as a decoy; and a competitive fascination with Xiaoyu Lei and Misaki Sakimiya following their violent encounters.