A bizarre environmental event in Kanazawa Prefecture 22 years ago caused the earth to fracture and surge upward to record heights, forming the isolated region known as The Lost Ground. Kazuma is a young mercenary residing in The Lost Ground, seeking any available work to survive its harsh conditions. He is among the few individuals gifted with the Alter ability, which enables him to coat his right arm and torso in a metallic alloy. When this mercenary crosses paths with HOLY, an order dedicated to suppressing and capturing those they label as Native Alter Users, and specifically with Ryuho, an elite member of HOLY, an epic rivalry commences.