Sadao Maō, originally known as Overlord Satan Jacob on Enta Isla, is a demon lord who ends up in Tokyo, Japan on Earth. He tries to make a living while trying to find a way back to Enta Isla. While his role was usually that of a villain during his time in Ente Isla, he has steadily progressed into heroism since living on Earth. This is shown in such acts like saving people from being killed by an earthquake, protecting the city from either demons or renegade angels, as well as trying to save Chiho and Emi.