On the verge of peace between two major factions, a demon appears, kills the lords involved, and then erects an impenetrable magic shield. The newly graduated mage Shiruka is on her way to be bound to serve a lord she doesn't know when she is attacked. (That's just the first few pages so I don't consider this a spoiler.)
One thing that the synopsis above doesn't mention is that this manga, while deadly serious overall, has some moments that are truly funny. Frankly I'm tired of all the depressing, dark, demented stories out there.
I like drama, but episodic humor to lift your spirits when things are dark is very welcome.
Hopefully this series will continue in the same vein.
The art is unusual, but not so much that it distracts from the story.
Finally, one thing that is RARELY seen in manga is the size of the "armies" involved. One attacker has 50 men in his "army". In medieval times, that was a reasonable force for one of the low-middle level nobility. Many barons might have 10 to 20 men. Very few mangas have this degree of accuracy.