Aliens took over and destroyed Earth many years ago and enslaved humanity and made them nothing but pets for the aliens

The aliens would hold a competition known as Alien Stage where any human sent to compete would have to sing a song, get the most points, move to the next round, or die on the spot.

Children that were decided to compete in Alien Stage were sent to a kindergarten known as Anakt Garden to practice literacy and singing to compete in the challenge once they were older.