There was an anime I seen a long while ago, but I don't remember the name. It was pretty unique, so I'm sure others will remember it.
There were fairies who fought for humanity. The girls was trained at a young age, and they didn't fear dying. The main person was a normal human, and he fallen in love with one of the older girls. They lived in floating cities. On the surface of the Earth there was monsters.
There was one part that stuck out. It was when the little girls was playing some sport between themselves, and a ball fallen over a cliff. They went after it, and it was at that moment explained that they were made to die. So they had no fear of dying.
Does anyone know the title?