Kaijin : Fallen World

It's the year 4045 and the world has fallen to ruin. Monsters called Kaijin roam the earth destroying and killing everything in their path. They first appeared during the great calamity, now called the cataclysm. At first we wouldn't even dream of subjugating these monsters but now we might have a fighting chance. In this world we find our protagonist, Isagi Kurozaki a 14 year old orphan who fends for himself in this cruel world.