Underground Country

Our ancestors once lived in a world on earth that was vast, rich, and safe. Until, they did something wrong. Not only the surface civilization was destroyed, but the entire world was destroyed. Radiation, storms, severe extreme weather and ferocious and violent mutant creatures... After discovering that they could not carve out a new living space for themselves on the ground, the remaining people took their survival technology and hid underground. The place was narrow, but could be developed artificially, and the products were barren, but they could survive. So the survivors settled underground, lived and multiplied. This is the origin of the underground state. It has been hundreds of years since the Great Disruption. And our story begins in a small town called Spice on the border of the underground country.