Justin emerges as the central antagonist commanding the Justices, a self-proclaimed order-enforcing faction within the virtual realm of "U." Operating without official sanction from the platform’s administrators, he wields a sponsorship-acquired laser handgun capable of forcibly unmasking users—a power exclusive to "The Voices," U’s creators. This tool fuels his delusion of being the realm’s rightful lawkeeper, though his methods prioritize control over justice.

In "U," his avatar contrasts starkly with his concealed real-world self: a towering figure with blond hair, piercing blue eyes, and pale skin, armored in gleaming white superheroic plating that embodies his self-styled heroic mythos.

Driven by obsession, Justin relentlessly pursues the Dragon, a mysterious entity accused of destabilizing "U." During Belle’s concert, he publicly attempts to expose the Dragon, then pivots to imprisoning Belle, threatening her with identity exposure unless she reveals her ally’s location. Her rescue by the Dragon’s AI operatives allows him to trace and obliterate their virtual stronghold.

His dominance fractures when Suzu, the protagonist, voluntarily reveals her identity and continues performing—an act that erodes his influence, triggering sponsor withdrawals. His escalating fixation on crushing her popularity further destabilizes his authority and psyche, though his final fate lingers unresolved.

Drawing thematic parallels to Gaston’s arrogance in *Beauty and the Beast*, Justin vilifies opponents to preserve his hero facade, pursuing dominance under a hollow guise of justice while dismissing ethical consequences.