In the year 2138, virtual reality gaming is booming. YGGDRASIL, a popular online game which is quietly shut down one day. However, two players named Momonga and Zero decides not to log out. As the game shuts down, Momonga and Zero are then transformed into their avatar, a skeleton wizard and a Dullahan becomes "the most powerful magic caster in the world." and " the most loyal and powerful dullahan in the world." As the world continues to change, with non-player characters (NPCs) beginning to feel emotion. Momonga and Zero decides on their course of action: for Momonga having no parents, friends, or place in society, this ordinary young man, Momonga decides to conquer the new world the game has become and Zero having a distant family , no friends , or place in society and being a lazy man decides to stay near his best friend in this quest.