In a world undergoing a sweeping "Magic-Industrial Revolution," where newly harnessed magical power drives machines and fuels the rivalries of competing nations, an immortal warrior named Kaim has wandered for a thousand years with no memory of his past. Cursed and blessed with endless life, he is caught up in the wars and schemes of the great powers even as fragments of his lost memories, and the countless joys and sorrows they contain, begin to return to him. Joined by fellow immortals and mortal companions, Kaim journeys across the world to confront a looming threat while grappling with the weight of his own eternal existence.