The premise alone, two legendary swordsmen fused into one body, one a harmless medicine peddler, the other a massacre incarnate, sounds like a gimmick until the show actually commits to the psychological horror of sharing your own skull with a killer. Yuya's pursuit becomes something stranger than a bounty hunt; she's chasing a man who might genuinely disappear the moment Kyo surfaces. The tonal whiplash from road-buddy comedy to genuine dread works because the show refuses to pick a lane, and neither does Kyoshiro.

Four years after vanishing in the chaos of Sekigahara's legendary battle, Kyoshiro resurfaces as a traveling medicine peddler on a rural highway, deep in debt and prone to lechery. Gun-toting bounty hunter Yuya Shiina tracks him down, having learned that the feared swordsman "Demon Eyes" Kyo, slayer of a thousand men, has been dormant inside him ever since a meteor struck the battlefield. While she hauls him off to collect the reward, an inhuman monster attacks and tries to devour Kyoshiro, and the assault wakes Kyo. What follows is an action adventure with comedy and fantasy elements, built around two legendary swordsmen and the secrets that bind them.