in the coldness

In a world where weird creatures began to wander around, their shapes keep changing whenever the troops of Gaia attack them, torture them for experiment to find out whatever they are and where the hell they come from. But the scientists form the academy of north Gianna almost find out nothing from those ugly creatures. No one except the higher ups and the government knows the case, but people start seeing them around the city and town. Rumors start to wander around the whole province. Rhena a student at the academy of northern Gianna, she gets her hand on files from her professors office that those creatures keep growing rapidly and starting to kill humans, she is so confused and surprised that those rumors were true.
Once Rhena and Kallias are assigned to work together to find out more about them.

What will they do when suddenly the creature start to attack the whole city? And why do they never get along almost killing each other ? Well not almost since one of them seems to hide there feelings.