Yamato's ordinary life crumbles the moment the mayor conscripts him to pilot Ω99, a colossal war machine that's been dormant since civilization tore itself apart. His city, Kisshou, is one of the last habitable places on a scorched planet, built around salvaged remains of ancient humanoid weapons called Legacies. Now bandits are closing in, desperate to steal the city's most valuable secrets, and the only thing standing between survival and annihilation is a teenager who'd rather be gaming than fighting for his life. Forced into a cockpit he never asked for, Yamato must figure out how to operate machinery designed for warfare while grappling with a truth his city has kept hidden. Every decision matters. Every mistake could mean the end of everything his community built from the ashes of the old world. The weight of that responsibility crashes down on him as fast as Ω99 can move, and there's no option to pause, reload, or respawn when real lives hang in the balance.