Noir, also known as Kuro or Black, is an orphaned teenage boy surviving on the streets of Treasure Town. He moves with lethal agility and advanced combat skills, effortlessly leaping between buildings and scaling structures to perch atop telephone poles, surveying the territory he fiercely claims as his own. A prominent vertical scar bisects his right eye, hinting at a troubled past and potentially impairing his vision. His punk-inspired look features graphic t-shirts bearing symbols like inverted numerals forming a yin-yang motif, accented by various urban street accessories.

Inseparable from his younger companion White, they call themselves "the Cats," surviving through theft and confrontation. Noir acts as the street-smart protector, exhibiting territorial aggression, while White provides childlike innocence and emotional balance. Their bond is codependent: Noir relies on White to stabilize his violent nature, and White depends on Noir for physical safety. Noir fiercely declares Treasure Town "his town," defending it violently against threats.

When yakuza enforcers working for developer Snake encroach, Noir's brutal assault escalates tensions. Snake deploys enhanced assassins—Dragon, Butterfly, and Tiger—to eliminate them. During the conflict, Noir fails to stop Butterfly from severely wounding White, leading to authorities placing White in protective custody. This separation shatters Noir. Deprived of White's stabilizing presence, he spirals into violent madness, manifesting a monstrous alter ego: "the Minotaur." This entity embodies his unrestrained aggression and detachment from reality.

Fractured and paranoid, Noir hallucinates, clutching a doll he believes is White while teetering on complete mental collapse. The Minotaur persona threatens to consume him until White's return. Their reunion culminates in Noir confronting and overcoming his violent alter ego in a climactic battle, choosing their bond over territorial dominance. The narrative concludes with Noir and White restored to their partnership, playing together on a beach, signifying Noir's return to emotional equilibrium through their interdependence.

Throughout this journey, Noir evolves from a territorial street fighter into a character confronting his capacity for violence, ultimately prioritizing his foundational bond with White over his possessive claim to the city. His orphan background and psychological struggles weave themes of trauma and resilience within an urban dystopia.