Shinsekai Yori | Tale of the Fiend
"It was about five hundred years ago.
A young man was wandering the mountains, picking herbs. Completely absorbed in his herb-picking, he reached the Holy Barrier.
He glanced outside the cordon and saw a large field of herbs. He had been reminded many times by adults that crossing the Holy Barrier was forbidden. If the need arose for whatever reason, he was supposed to be accompanied by an adult.
He saw a fiend coming for him. He was about to lead the fiend back to his village. If he followed the path to the village, the fiend would obliterate it. What should he do?
”My life matters not. The fiend should never find the village.”
And so, no fiend has ever found our village so far.”