Maou and Emi's dynamic stays razor-sharp even when the show stops trying to look like it cost money. A kid who might be theirs shows up, and suddenly a demon lord's corporate climb becomes about whether he actually wants to stop running from something real. The animation tanks hard enough that you notice it within two episodes, but the writing refuses to follow, every scene between these characters lands because they've earned four seasons of history to fall back on.

Maou, once the feared Demon Lord Satan of Ente Isla, is now a model employee at MgRonald's in Tokyo, still aiming to climb the corporate ladder and one day rule Earth. His plans stall when a portal delivers a toddler named Alas Ramus who treats him and Emi, the hero who defeated him, as her parents. Emi reluctantly agrees to help raise her, but the archangel Gabriel soon arrives demanding both the girl and Emi's sacred sword, warning that the world will be destroyed otherwise. The former enemies have to set their differences aside to protect her. The season mixes comedy, fantasy, romance and slice of life, pairing the joke of an evil overlord leading a mundane life with unexpected family ties.