Set in an alternate, historically-rich Japan, the story follows Shichika Yasuri, the seventh head of the Kyotoryu school of swordless martial arts, who lives in isolated exile on the remote island of Fushigi. His secluded existence is disrupted by Togame, an ambitious and eccentric shogunate strategist. Seeking to atone for her father's failed rebellion, Togame tasks Shichika with collecting twelve legendary, corrupted swords forged by the master swordsmith Kiemon Shikizaki. These blades possess anomalous, almost supernatural traits that corrupt anyone who wields them. Togame offers Shichika her love as collateral, binding him to her quest and launching the duo across Japan.Initially viewing Togame merely as a master to obey, Shichika gradually develops genuine romantic feelings for her. Along their journey, they confront formidable opponents, including rogue ninja, religious fanatics, and eccentric wielders holding the remaining Shikizaki blades. Each encounter forces Shichika to adapt his unique combat style—where his own body acts as the blade—against lethal, enchanted weaponry.Among their most dangerous adversaries is Hitei, a rival strategist, and her deadly bodyguard, Eiemon. Throughout the trials, Shichika is forced to kill many rivals, pushing his physical and emotional limits while Togame manipulates political factions
behind the scenes to secure
the collection.The narrative reaches its devastating climax when they infiltrate the Owari Shogunate's stronghold to retrieve the final sword. Here, a dying Eiemon reveals a shocking conspiracy: Togame’s family was actually responsible for the historical rebellion, and the shogunate orchestrated the sword hunt not to unify the country, but to eliminate both the lethal blades and Togame herself, preventing her from avenging her father. Moments after this revelation, Togame is fatally shot by Hitei. In her dying breaths, she reconfirms her love for Shichika and gives him a final, contradictory command: to forget about her and never seek revenge.Grief-stricken and disillusioned, Shichika abandons his traditionally passive nature. Instead of obeying her final wish, he goes on a ruthless rampage through the shogunate's castle, easily dismantling the shogun's elite guard using the combined powers of all twelve Deviant Blades, which he had finally gathered. Confronting the Shogun face-to-face, Shichika spares him upon realizing that the Shogun is merely a puppet and that true political power has shifted. Having shattered the Shikizaki blade collection to prevent further bloodshed, Shichika chooses life over suicide. He departs the castle alongside Hitei, who adopts Togame’s former catchphrases and ambitions, embarking on a new journey to witness the changing, modernizing world that Togame never got to see.