I remember when the skies parted and the stars broke through

Half of the world's population was suddenly stricken with an undying ambition. An ambition to annihilate the rest of humanity. Teachers and students alike banded together and created great weapons, both physical, and metaphysical. Construction workers and war veterans ruthlessly trained for combat, perfecting the art of war, innovating murder. In the first week, billions were eradicated.

Standing in an abandoned office building is a lone salaryman, watching his inevitable fate come closer and closer. But in the depths of his despair, he suddenly feels a strange power coursing through his veins. He's granted a chance to fight back. Though he realizes that even with the immense strength he has been bestowed with, he will eventually be killed like the rest. But he's beyond that at this point. All that he wants to do now, is give them hell.