Set after the events in the anime .hack//Sign, the story begins as players take on the role of Kite, who joins his real life friend, Yasuhiko, in the popular MMORPG The World. Yasuhiko is better known as Orca, a player of legendary status in The World, and rightly earned. From the message boards within the game, Kite learns that Orca has helped many beginner players set out, just as he does Kite. However, what starts off as a simple crash course in the game's mechanics turns horribly wrong.
Kite and Orca encounter two strange creatures: Aura, who appears as the floating ghost of a young girl, and the monsterous humanoid figure known as Skeith, who is chasing after Aura. Orca soon gives chase after the pair but ends up over his head as he battles Skeith. The battle ends with Skeith using a strange ability on the legendary player. When Skeith turns his attention to Kite, the legendary hacker Helba intervenes, and things begin happening very quickly and the game's server crashes.
Kite soon discovers that Yasuhiko, Orca's real life persona, lies comatose. To make matters worse, Yasuhiko is not the only player of The World in this condition.