A long time ago, there was a legend circulating in the human world. It was said that there was a place called the Holy Land, where gods lived and had various magical abilities. The Holy Land was peaceful and beautiful, and every ten years they would select humans from the human world to enter the Holy Land and grant them abilities. But in the hundred years since a great disaster broke out in the human world and people transitioned from the surface to underground life, no more legends about the Sanctuary people have been released, and humans have gradually forgotten about them. My story begins a hundred years later in the underground world.
Concept: Creatures with intelligence, self-restraint, and independent thinking are collectively called humans. The sanctuary is already changing, but what about the human world?