Monster x Monster

is a Japanese manga series written and illustrated by Nikiichi Tobita.

Plot
Once upon a time, this world was ruled by beasts. Humanity no longer sat at the top of the food-chain, they are the monster’s prey. However, those who would stand up against the monster’s gathered together and continued to battle against the monsters in order to survive against the beasts rule. Since then, centuries have passed…and now the battle against the monsters has become the hunt for the monsters.