The main hook of the story is in its gradual revelation of the state of the world 1000 years after psychic powers appear in humans. The opening episodes show, in small, unnarrated introductory snippets, that things got bad, but the key details are left out until an infodump in episode 4; after the "ground rules" of the history are established, the remainder of the story is focused on present-day problems and people trying to solve them - with a few secrets left until the end. We follow a group of children as they grow up and lose their innocence, in all senses of the word. Along the way we discover everything that went wrong. Despair for a hopeless situation permeates most of the scenario, yet the conclusion still manages a mildly, reservedly optimistic view.
If you are watching this, it's for the story, more than anything else. Anime stories that successfully deal with something this complex and nuanced do not come along often, and to no surprise, the story comes from a novel adaptation. Themes of class struggle, othering, and uncontrolled power feature prominently. The main characters, despite being powerful psychics, often find themselves unwitting pawns in some scheme, with their lives in danger.
As one might expect from a TV anime adapting a full novel, animation falls into a secondary role, and A-1's treatment has some occasional dips in visual quality, budget-saver stills, abstract visuals, etc. These things don't interfere greatly with the story's tension, which is built up similarly to series like Kino no Tabi or Mushishi - quiet, with punctuated moments of violence. It shows enough to stir the imagination and leave you hungry for more. No filler OP is used - it cold opens, shows a brief title, and then proceeds, so you're getting longer episodes than is the norm. The audio works in an effective complementary role, cuing in the viewer to a possible deception with every little remark, but leaving the answers until much later.
