Tatara, a wandering blacksmith, traverses a mythic Japanese landscape with his grandson Madara, forging and repairing intricate mechanical prosthetics known as "gimmicks." Their nomadic existence centers on aiding rural communities, until Emperor Miroku’s demonic envoys, the Mouki, ravage a village under their protection. Tatara perishes in the assault, his death igniting Madara’s awakening to the hidden potential within his own mechanized form. This tragedy propels Madara toward a confrontation with Miroku, as Tatara’s teachings and artistry—a fusion of ancient mysticism and nascent technology—linger in the tools and resolve he bestowed. Though Tatara’s story ends with the invasion, his craftsmanship and guidance endure as pillars of Madara’s rebellion against tyranny.