The top player of the online game YGGRSAIL, "Momonga," sits in the Throne Room, waiting for the game to end. He expects the servers to shut down while he does nothing, but suddenly receives a notice inviting him to take part in the "Holy Grail War." Thinking it's a new game from the same publisher, Ainz accepts without a second thought. And so the Overlord, who should have transmigrated to another world to throw his weight around with his minions and argue with thin air, gets swept up in the grand epic of the Nasuverse, all through a series of misunderstandings.
