Moimon

The mysterious creatures that suddenly appeared are… Moimon. A charming exterior, balanced against an inherent savagery and tough bodies. At first glance, it appeared that humanity had finally established a master-servant relationship with them through training… But as a new found ferocity spreads through wild Moimon, the continued survival of the human race is in question.

Kakeru is a boy from a warrior tribe that survives by hunting Moimon. Shimizu is a girl dreaming of adventure. Together, they set off to gather clues to stop the ferocious mutation of these creatures. And so rises the curtain on a new and exciting monster battle action series featuring bizarre creatures called Moimon and the boy who hunts them!

(Source: Manga UP!)