The world has already fallen. The future has unfolded into a horrifying war against the parasitic virus “Gastreya”… and that war was lost. The remnants of humanity have been cornered and continue to live in despair. Rentarou and Enju are employees of Civil Defense, whose job is to fight gastreya. And as if constantly exposing their lives to mortal danger wasn’t enough, they are about to face a disaster that could wipe out the entire Tokyo Zone… (с)