The story begins with Yggdrasil, a popular online game which is quietly shut down on its last day. Momonga decides to stay until the last moment in his beloved game and wait until the force logout. Unexpectedly, the server does not shut down, leaving Momonga stuck in his skeletal body, in a world that is neither earth nor Yggdrasil. The powerful ‘Overlord’ must now discover this new world and the dangers it contains. Accompanied by his guild’s NPCs, who are now living creatures with their own agendas, their adventure now begins.