The story commences as a Sinanju Stein unit, produced by Anaheim Electronics and currently under the control of the Neo Zeon unit known as Sleeves, forcefully breaches through the Earth's stratosphere. The Nahel Argama's Unicorn promptly takes flight and heads towards the Sinanju Stein for confrontation. Meanwhile, the Banshee Norn and Phenex are en route to provide support.