Shichika Yasuri performs Kyotouryuu, a method in which the user's own body is used like a blade, in an Edo-era Japan rich with sword-fighting systems. Shichika, the enigmatic seventh head of the Kyotouryuu school, lives peacefully in exile with his sister Nanami until the insanely ambitious strategist Togame bursts into their lives one day. Togame boldly asks Shichika to assist her in her endeavor to gather twelve rare swords known as the "Deviant Blades" for the shogunate. Shichika accepts, more concerned with the girl herself than with petty politics, and thus embarks on a voyage. The strong wielders of these famous weapons, as well as other power-hungry forces seeking to undermine Togame's goal, stand in their way.