Regarded as humanity's chief adversary, fierce dragons of an ancient line roam the world. Only two methods effectively defeat them: chilling their blood with silverine—an effect from silver arms—or exposing their flesh to blazing sunlight. Young sharpshooter prodigy Leonica travels with her close companion Ragna, who seems to lack the talent required for their trade. Moreover, many regard Ragna as cursed because dragons repeatedly target him and kill his loved ones. Still, Leonica sees promise in Ragna and willingly partners with him. Likewise, Ragna believes Leonica shields him from misfortune thanks to her extraordinary might. His confidence wavers when Ragna dreams of Leonica's death, interpreting it as a prophecy. When the foretold day dawns, he confronts his future self, who grants him vast power and memories from the future to safeguard Leonica. To achieve this, Ragna must ally with a shadowy figure called Crimson and eliminate all dragons forever. Together, they forge a pact that will test their resolve as the looming threat of fire and steel looms over kingdoms to reclaim peace from dragon scourge.
