The story focuses on a Wavemaster named Tsukasa, a player character of a virtual-reality massively multiplayer online role-playing game called The World
. Tsukasa wakes up to find himself in a dungeon in The World, but he suffers from short-term memory loss as he wonders where he is and how he got there. The situation gets worse when he discovers he is unable to log out and is trapped in the game. From then on, along with other players Tsukasa embarks on a quest to figure out the truth behind his abnormal situation.