Desert Kingdom centers around Aspasia, a princess of the magical Kingdom "EVUU".

Aspashia is a majin princess that lives in the magic kingdom of EVUU. One day, her magic suddenly disappears and her father, the king, says it must be because her mother was human. Aspashia learns that in order to get her magic back, she must travel down to earth and grant the wishes of humans. By granting small wishes, she will get a small amount back, but in order to get a large amount back, she must grant true, large wishes. However, people keep these wishes secret, so it will take time for her to figure them out, time that she can’t use to grant small wishes. Aspashia has a limited amount of time to get all her magic back, or she’ll have to remain on earth as a human for the rest of her life.