Li is a man with a secret. The world changed and a wall has been built around the city that meets the sky.
Contractors are humans who have accepted powers from beings outside of normal space. They have a price they have to pay, a compulsion they have to do. Contractors lose their ability to empathize when they gain their powers and they become totally focused on their job.
But as the series moves forward you start to wonder about Li. He is emotional and kind, even loving. Which should not be possible for someone who is a Contractor. So is he really a contractor?
All around this is an interesting anime. Lots of places for it to go and I find I am enjoying it.