Iori Tōjō, adopted heir to a business magnate, faces lethal opposition from his own family determined to prevent his inheritance. This deadly familial conflict designates him as their primary target. An undercover police officer, aware of the plot, attempts to warn Iori through Tomoe Ōjima.

When Tomoe delivers the warning, Iori learns his family has hired Green Ship to eliminate him – a stunt training school covertly operating as an organization of assassins and guerrilla fighters. His adoptive family's orchestration of this assassination plot forms the core conflict driving his story.

Tomoe Ōjima subsequently vows to protect Iori from Kazusa Himuro, her former romantic interest and Green Ship trainer, who is now tasked with carrying out the kill. This establishes Iori Tōjō as a protected figure whose survival hinges on evading the organization hired by his family.