Shinobu Saiga is the reincarnated form of Kara-ou, a legendary commander who sacrificed himself 900 years ago to seal Kuna-hi, the ruthless leader of the rival You no mono faction, ending their celestial war. In the modern era, Shinobu reemerges to confront the resurgent You no mono, fighting alongside his steadfast lieutenant, Kiba. His rebirth binds him to the eternal clash between the factions, which seeks to shield humanity from supernatural annihilation.

As the reborn Kara-ou, Shinobu commands the Kuu no mono’s forces with strategic precision, relentlessly suppressing the You no mono’s dark ambitions. His mission intertwines with Ryosuke Sakiya, a high school student wielding rare psychic abilities targeted by their enemies. Shinobu’s efforts extend to guiding and defending those like Ryosuke, who become entangled in the conflict between the Kuu no mono’s Jutsusha—guardians bearing hereditary powers—and the You no mono’s malevolent forces.

Shinobu operates with unwavering pragmatism, prioritizing threat eradication while reconciling his dual identity as both mortal and ancient leader. His alliances and rivalries reveal a tactical intellect honed across lifetimes, driving his unyielding dedication to the Kuu no mono’s cause amid the shadows of his past.