When a popular fantasy MMORPG shuts down its servers, one guild leader, the skeleton mage, Momonga, finds himself transported to a real fantasy world trapped inside the body of his avatar. His guild's fortress has been transported to an unfamiliar world and the inhabiting NPC characters gain sentience and look to Momonga as their supreme ruler–an overlord as it were. With his extensive knowledge of magic and powerful, fanatic minions following his every whim, Momonga continues to roleplay the part of the evil overlord to the extent that domination of this new world is not an entirely unappealing option.