World War III, taking place in the late 1980s, resulted in a nuclear winter, forcing humanity underground. Over time, they developed "exosuits", machines designed to block out nuclear radiation and explore the changed world. Now, in 2150, they are only tools of perpetual war, especially for the European Imperial Federation and the New Soviet Republic, two regional rivals forever locked in tensions.

Wilhelm Frei aspires to be one such weapon of war. Intent on hunting down the man who took everything from him, an NSR pilot known as the "Red Reaper", he joined the military for a chance to get even.

After a fortuitous twist of fate, he finds himself taking part in an experimental program, "Project Cyberitter", and becomes one of the first to pilot a "cybersuit", a high-powered exosuit with a direct connection to his brain.

Alongside his fellow Cyberitters, he is tasked with leading a military campaign eastward, blissfully unaware of the trials in the way of his revenge...