The story begins with Yggdrasil, a popular online game which is quietly shut down on its last day. Our protagonist Momonga decided to stay until the last moment in his beloved game and wait for the force logout. Unexpectedly, the server did not shut down and Momonga is stuck in his skeleton body and got transferred to another world. "The powerful Overlord" needs now to discover a new world and face the continuous challenges.

Having no parents, friends, or place in society, this ordinary man strives to take over the new world the game has become.