In a world void of civilization and law, marauders have become de facto overlords and malevolent spirits lurk at every turn, causing innocent individuals to suffer endlessly. During his travels with his kin, Sona Yuki is assailed by bandits, who slaughter his kin, leaving him as the solitary survivor sporting a serpent sign on his hand. With death looming, a woman called Garami accosts him and offers him a proposition of either continuing to exist in the cruel terrain or die peacefully. Yuki aspires to live, and after pledging himself to her, Garami, who peddles weaponry and is a gun-for-hire, affords him a new beginning. Nevertheless, as they traverse towns in search of clients, Yuki is forced to wrestle with the ruthless and unyielding facts of the world they occupy.
