There exist enigmatic machines, dubbed "Tremble," in this realm. Their origin and purpose is a mystery. What is certain, though, is that they evolve and pose a threat to humanity. The only defense is to attempt to eradicate them, but a select few have mastered the art of commanding them to gain an upper hand - these are the Breeders. These exceptional individuals lead a challenging existence, constantly pursued by those who view them as outlaws. Ion, however, is not deterred. In emulation of his father, he has chosen to pursue the path of a Breeder and tame the Tremble!
