The opening twenty minutes don't matter. The show knows you're coming for the moment Shiki discovers what he is, then watches everyone around him decide whether that makes him a weapon or a person. The animation carries you through the slow buildup, but the real hook is simpler: a protagonist who doesn't want power, doesn't crave revenge, and genuinely questions whether the agency fighting for him is worth fighting for at all. By the time you hit episode six, you're not watching a shonen about bloodlines. You're watching a kid caught between two factions that have forgotten they're both human, trying to find a reason to believe in either side.
Shiki Ichinose's ordinary life shatters when a violent attack reveals the truth: he carries the blood of the Oni, ancient demons that have hidden among humanity for centuries. This discovery thrusts him into a shadow war spanning millennia between two opposing forces. The Momotarou Agency, descendants of the legendary hero, hunts Oni with relentless conviction. The Oni Agency protects their own, viewing themselves as victims of an endless cycle of persecution. Caught between both worlds, Shiki must understand what his inherited power means and where his loyalties truly lie. The series blends supernatural action with noir sensibilities, treating this hidden war as a gritty, morally complicated conflict rather than a simple good versus evil story. Dark atmospheres permeate tense confrontations where neither side holds absolute justification. Shiki's journey becomes about more than survival: it's about answering whether destiny is something you inherit or something you choose. Viewers drawn to character-driven action with complex mythology and moral ambiguity will find compelling stakes here.