Popular version: Something went wrong at the bottom of the underworld, causing chaos in the underworld. The ruler of the underworld fell and the hell became ownerless. As a result, the hell lost its ability to govern the human world. Finally, out of desperation, the human world was made an "autonomous region." Then a large number of ghost certificates were issued to the human world, and mankind entered the era of catching ghosts with certificates!
Literary version: does not exist -_-
Note: Warm reminder, this is a non-horror and suspense text, suitable for men, women and children. You can read it as a humorous monster-killing and upgrading text.
