Mirena, the demon princess obsessed with humans. William, the demon prince with incredible powers to change reality. Both of them are children of Phobos, the king of the demon world. They lived normally, or until the faithful day everything changed. When a powerful switch caused the two demon siblings to inhabit the human world. Once Mirena and William, Now Mickey and Billy. As they adventure around the human world, they meet both friends and foes, and a blonde haired human boy that Mirena takes a liking to.