Two years ago, the Angel Trainee Flonne was sent to the Netherworld to assassinate King Krichevskoy. However, when she arrived at the Overlord's Castle, it was covered in flames. For the next two years, Flonne searched for her target, narrowing her search to a local dump. She found a coffin with Krichevskoy's emblem on it and tried to carry out the assassination. However, it turned out that it was not Krichevskoy, but his son Laharl. Learning that his father has died, Laharl set out to claim the title of Overlord for himself. Flonne and another demon by the name of Etna followed after him.