The main character, Saki, and her friends grow up in this society and learn their powers like the other children. Unlike the others, though, Saki's group pushes the boundaries set by their elders. They manage to learn something of world history and the sometimes draconian methods used by their leaders in keeping society under control. But even those methods can't prevent every disaster.
A good chunk of the story revolves around an intelligent animal race called Monster Rats. They have no psychic powers, and treat the humans as gods. And the humans behave as such, putting restrictions and rules in place for the Monster Rat society. A small number of powerful individuals holding sway over a large population...nothing could possibly go wrong with that, right?
I really enjoyed the world-building of From the New World, and most of the mystery aspect of the story. There's several points where I thought the plot dragged a bit, and some of the interpersonal relationship stuff seemed awfully contrived to me. But those are fairly minor nitpicks, and overall the show kept me entertained and interested throughout.