Youngsters called Kildren, who are destined to live eternally in their adolescence. The Kildren are conscious that every day could be the last, because they fight a war as entertainment, organized and operated by adults. But as they embrace the reality they are faced with, they live their day-to-day lives to the full.
The animation is awesome and beautiful but the story and plot, as in last I.G. productions I've seen, is overcooked in a intent to be deeper than it actually is.