Shuranosuke Sakaki, a master swordsman of Japan's Tokugawa era, bears a distinctive purple attire and the "Scythes of Death" crest on his back, noted by some as resembling a swastika. He resides within a dilapidated cemetery hut, compensating the caretaker with gold earned from his services. His combat prowess is evident when he bisects a giant white tiger in a single stroke during an escape in Edo.

He wields his sword Onimaru with lethal precision, frequently bisecting opponents vertically or horizontally, decapitating them, or severing limbs. In one instance, he nonchalantly slices open a female pickpocket's robe as punishment, leaving her exposed. He accepts a mission to rescue Princess Mayu from the Seki Ninja for payment, though he later refuses the reward after succeeding.

During the mission, he engages in a sexual encounter with the pickpocket Oren, who initially intended to kill him but became physically drawn to him. He rescues Princess Mayu, who propositions him; they share intimacy at an inn where he reveals murdering both his parents and younger brother.

His combat encounters include defeating supernatural foes: a water-dwelling kappa, an accursed soul manifesting on a lake, and specialized Seki Ninja assassins. After returning the princess, his employer Daizen Imura betrays him, ordering his execution for contacting her. Sakaki responds with contempt, comparing himself to a stray dog refusing food from one who threw stones, and departs without payment.

The narrative concludes as he encounters the martial arts assassin Marōji, who remarks on their shared "scent of blood"; Sakaki retorts that Marōji should be grateful the blood isn't his own. Aspects of his background remain, including his residence in the cemetery, the circumstances of his family killings, and his connection to an unresolved Christian antagonist seen near a burning cross.