The Demon Lord Satan and one of his generals, Alciel, escape the world of Ente Isla through a gate to modern Tokyo, Japan after being confronted by the Hero Emilia and her companions. However, due to the lack of magic in the modern contemporary world, both Satan and Alciel were changed into humans because of the lack of magic so they can keep their original forms. Satan takes a part-time job in a fast food restaurant named MgRonald while Alciel serves as his houseman. The powerful Satan now a human and named Sado Mao he bunps into a girl who is actually the Hero Emilia, who now goes by Emi Yusa. The story then unfolds and explores the personalities of each of the characters and their moral values. More characters show up from Ente Isla and they too face the new world dilemmas, often comically. One of the characters is named Lucifer he is my favorit in the anime he is strong and has a nack for computers, he helps or not help buy spending Sados money and always putting them in even more debt. Now the story is how will they get home and how can they get their magic back. 

So far the Satan and his generals find out that the only way to get magic is by feeding on the fear and anger of humans in our world or trying to find anomalies that give off magic.