From Manga-Heaven:

Yuma is a girl in love! Quite typical you say, but you see, Yuma is also a mage and mages in this world have to be rather discreet. Her boyfriend to be, Kaname, is a bright, handsome, kind young man... who is allergic to magic.

If things couldn't get worse for poor Yuma, the Underground Empire is about to declare war on every mage in the world! What's a girl to do?

The Tenshou Azuchi period is the period of the secret awakening of "Jiki", the demons sealed by gods. The Jiki eat on everything in the human world, but no human can notice the Jiki's presence. The only ones to stop them are these adventurous young mikos and Bateren people.