In a war-torn region of the Far East, feudal lords clash endlessly for dominion while an Emperor rises to unite the fractured land under imperial rule. Four legendary swordmasters, the Kenseis, view this consolidation as a threat to the samurai code and mobilize a rebel army to oppose the throne's authority. Unaware of these grand conflicts, a young female assassin trained in secret by a mysterious sage emerges from her isolated village to undertake her inaugural assignment, setting her on a collision course with the forces reshaping the continent's fate.