Junpei Touma balances life as a college student and part-time rock star before a chance encounter with a mortally wounded stranger hurtles him into a lethal conspiracy. Entrusted with a cryptic floppy disk detailing advanced weapon systems, he joins forces with the Rutz Detective Agency—composed of Akira Nagareyama, Keiko Yamazaki, and Kumiko—to decode its secrets. Their investigation unravels a web of political collusion centering on the shadowy munitions conglomerate Yotsuboshi, whose operatives escalate from surveillance to outright violence: assassins stalk Junpei’s every move, allies vanish under dubious circumstances, and mechanized threats ambush him in broad daylight.

Though a near-fatal motorcycle crash leaves him battered, Junpei’s resolve hardens. His impulsive nature clashes with a dogged sense of duty to dismantle Yotsuboshi’s operations, propelling him into increasingly perilous showdowns. The narrative spotlights his resourcefulness under duress and loyalty to the agency, though his past remains opaque, his motivations tethered to thwarting immediate threats rather than personal reckoning.

The conspiracy’s climax hinges on Junpei’s race to expose Yotsuboshi’s machinations, leveraging the disk’s data to dismantle their influence. The story confines itself to this central struggle, prioritizing tense, action-driven revelations over extended character backstory or post-conflict trajectories. Its scope remains anchored to the OVA’s events, with no supplementary arcs explored beyond this contained narrative.