Kazuma fights with his entire body turned into a weapon, raw and ugly, no grace, just survival instinct sharpened into combat. The Lost Ground is a scar on the world, and everyone in it is scarred too; the show doesn't pretend their violence is noble. Two mercenaries on opposite sides of a war neither of them started keep finding reasons to fight each other instead of the people actually pulling strings, and that obsession is the only honest thing either of them has.
Two decades after a cataclysm buckled the earth upward, the Kanazawa wasteland known as The Lost Ground has become a lawless frontier where survival means taking whatever jobs come your way. Kazuma operates in this harsh terrain as a scrappy mercenary, one of the rare individuals born with an Alter: a supernatural ability that lets him harden his arm and body into impenetrable metal. His precarious existence shatters when he crosses paths with Ryuho, an operative for HOLY, a powerful military organization hunting down Native Alter Users like Kazuma. What begins as a violent clash evolves into something deeper: a personal rivalry that neither man can walk away from, each driven by convictions about what the Alter truly means and who has the right to possess such power. Caught between individual freedom and institutional control, Kazuma and Ryuho circle each other across The Lost Ground's fractured landscape. Their conflict isn't just about physical power but about fundamentally different visions of what society should become in this broken world.