Ryūzuki Kojirō operates as a Kouga clan ninja within an anti-Nobunaga coalition, specializing in strategic coordination and combat against Oda forces and the cyborg enforcer Ginnai Doma. He executes critical missions targeting Ginnai, including a team ambush during the cyborg's rest period using poisoned darts and close-quarters tactics. This assault inflicts initial damage but triggers Ginnai's lethal retaliation, causing heavy team casualties. During the final confrontation, he supplies Shishimaru with a spare sword for the decisive strike that destroys Ginnai's body, though the ensuing nuclear blast forces extraterrestrial evacuation for survival. His parents died by Ginnai's hand approximately eighteen months prior to these events. A flashback shows him prioritizing mission objectives over immediate vengeance, compelling Hayabusa to leave their village against her protests to avenge their parents. This loss shapes his pragmatic yet conflicted approach toward Ginnai. In manga continuity, his tactics feature deception and sabotage: he impersonates Ginnai to claim credit for assassinations like Dosan Saito and engineers a castle's destruction with pre-planted gunpowder. Later, he assists Shishimaru's escape from Ginnai and devises trap-based countermeasures against the cyborg's immortality. His character arc evolves through alliance-building, transitioning from skepticism about Shishimaru's impulsive vendetta to recognizing collaborative necessity against technologically superior enemies.