Ten thousand years later, on Earth, the land was occupied by unknown creatures, and humans had to find a new place to live. After discussion by the prime ministers of various countries, some humans went to live in sky cities, while the remaining civilians all lived in underground cities.
Late at night, the evolved monsters quietly entered the dungeon, and the dungeon turned into a purgatory on earth. Unknown to the nobles who lived a paradise-like life in the sky city, danger also came quietly.
Intention: There is no class in life. I hope people can boldly pursue the life they want and love boldly.