Shichika Yasuri practices Kyotouryuu, a distinct sword-fighting technique that uses the user's body as a weapon. Living in seclusion during Japan's Edo era with his sister Nanami, their peace is disturbed by Togame, an ambitious strategist with a mission to collect rare swords known as the "Deviant Blades" for the shogunate. While initially drawn to Togame's personality, Shichika agrees to help her despite being uninterested in her task. Together, they face perilous challenges, battling skilled wielders of the legendary swords and other adversaries who seek power and stand in the way of their mission. Amidst the treacherous journey, the two must come together to overcome their foes and emerge victorious.