In 2012, due to the nuclear disaster, some humans were infected and became mutants. They were deformed in appearance, with extremely large skeletons, great strength, and hard skin. They had strong vitality but were unable to reproduce. The uninfected survivors established a federation.
Mutants hate the Federation, but hot weapons cannot harm them. The Federation develops cold weapons made of special materials, establishes the Federation's First Military Academy, and trains an army that can fight against mutants.
At this point, the battle between the two sides began.