The year is 2138. The virtual reality somatosensory online game "YGGDRASIL", which once caused a sensation, is about to be discontinued. Player Momonga is quietly waiting for that moment alone in the Great Underground Tomb of Nazarick, the base where he once prided himself on his companions and glory. However, an abnormal situation occurred where he did not log out even after the end time. NPCs acted according to their own will, and not only that, a different world that had never been seen before unfolded outside of Nazarick. In order to find his former companions, Momonga called himself Ainz Ooal Gown, a guild name, and decided to make a name for himself in another world. Together with his subordinates who swore absolute loyalty, he marched into a new area. The ruler of death who holds the world in his hands has returned again! !