Constructed solely for war, sayabito are fearsome human weapons who are tightly bonded to those who wield them. In the wake of a great war, fiery and impatient Rivia and her willowy, cautious partner Kuifa roam the land in search of sayabito who lost their wielders in the conflict, in order to register and protect these vulnerable sayabito before they wither away or are exploited. Though Rivia and Kuifa frequently exasperate each other with their clashing approaches, they share one common goal: to carve out a life in the peacetime for which they, and others like them, were never meant.
Her recovery uncertain after a brutal battle, Rivia’s thoughts wander to when she awakened long ago. In the dreary underground halls she’s confined to, Rivia learns a grim truth—that she’s to be a mindless puppet meant to further her addo’s ambitions. But by the time his scheme falls apart, Rivia is utterly broken—tormented by the voices of those she was forced to kill. Before she can begin her journey of healing, her new companion Kuifa must help her back on her feet.