When the lord of demons and his horde waged war against the humans in their realm, a hero vanquished their army. Cornered, the Devil fled through an interdimensional portal to Earth. He vows to one day reign again, but until then... he needs a job!

When Emilia the hero finally tracks down the ruler of demons here on Earth, he's not exactly what she was expecting. Which may or may not make her a little crazy.

In the aftermath of the cave-in, Emi sees a side of Maou that doesn't jibe with the demonic king she knew in Ente Isla. Meanwhile, everyone sees a side of the landlady that nobody could have expected...

Lucifer is wrecking the neighborhood in a big way, and he's brought along some unexpected friends! To save both themselves and their new Earthly home, can Emi, Maou, and Ashiya do the impossible and... work together?!

Back in Ente Isla, the other high priests find out about Olba's betrayal. Meanwhile, Lucifer's moved into the Devil's Castle and gotten Maou and Ashiya into school ghost stories.