Kazuki Fuse operates within an elite counter-terrorism unit in an alternate-history 1950s Japan, enforcing suppression of anti-government insurgents with rigid obedience to protocol. A pivotal mission ignites a moral crisis when he disobeys direct orders to eliminate a teenage courier linked to terrorists, his hesitation allowing her to trigger a fatal explosion. The fallout brings disciplinary retraining and fractures his psyche, seeding relentless guilt and eroded self-assurance.

Haunted by failure, Fuse visits the courier’s grave, encountering Kei Amemiya, who poses as the girl’s grieving sister. Their bond deepens through fragmented exchanges laced with vulnerability, until Kei’s identity unravels as a fabrication by a rival intelligence network targeting his unit. This betrayal thrusts Fuse into a labyrinth of political conspiracy, tearing at his allegiance to duty and awakening forbidden emotional ties.

His unit, Kerberos, grapples with internal dissent and external adversaries like the Wolf Brigade—a shadowy counterintelligence force exploiting Fuse’s connection to Kei to purge government rivals. Though genuine attachment to Kei emerges, institutional imperatives eclipse personal yearning. In a climactic directive mirroring the Little Red Riding Hood allegory, Fuse executes her to thwart her captors, finalizing his metamorphosis into a weapon of the state. This surrender to systemic brutality marks the annihilation of individual conscience.

Fuse’s arc traces the corrosion of empathy under authoritarian machinery. Once a principled soldier balancing compassion with discipline, his descent into ritualized violence lays bare the cost of survival in a regime fueled by subterfuge. His tragedy mirrors wider institutional rot, framing him as both pawn and perpetrator in a cycle where humanity crumbles beneath the machinery of control.