If you were looking for a game specifically, there are two distinct titles often confused with the anime: Shinsekai Yori -Tactics-
A group of children in a seemingly idyllic, post-apocalyptic society learn to master psychokinetic powers ("Juryoku"). As they grow, they uncover dark, terrifying truths about their world, human nature, and a history of cruelty. shinsekai yori from the new world complete n install