There's drama/romance in it seeing that Louise has the tsundere trait. She summons a "familiar", and what they go through is typical and not heavy on the heart. There's nothing epic battle-wise- King's in foreign parts wanting to gain territory, the usual.
It's comical at times, harem and ecchi, for the better or worse in cases.
If you've seen Shakugan no Shana it's the same cast for the main characters and some of the same traits, though SnS is superior in my opinion.
Hope that helped a bit..I'm not to good on reviews, meh.
There's 3 seasons also, so if you enjoy, there's more for you.