In 2047, humanity stumbles upon a rare energy-rich ore named 'Gaimetal', sparking a global rush in mining operations. By 2075, relentless assaults from Gaist, metallic creatures infused with Gaimetal, prompt the creation of the GCG (Gaist Crusher Garrison). Tasked with combating these foes, the GCG deploys Gaist Crushers in 2064—individuals clad in unique Gaimetal armor, the 'Gaist Gear'. As they confront Gaist threats, a shadowy group known as the 'Erasers' adds a new layer of danger to their mission.