Academy City. A city of science, of fact and powers. Here, humans can come to develop supernatural powers of their own and become Espers. Mikoto Misaka is the 3rd most powerful esper.. however, she currently feels powerless to help her friend Asuna, who is still stuck in the virtual world, created by the mad man Kayabe. Along with her friend Touma Kamijou and Kazuto Kirigaya, she plans to go back into the virtual world to rescue her friend.. however, the IRL dangers are multiplying. Powerful espers are taking interest in the world of swords and magic.. and it's creating quite a ruckus.

She woke up one day... in a world she knew nothing of. She woke up not knowing her name, or who she was.. all she knew, was that the world she currently resided in, wasn't real.. Who was she? Was she just a phantasm doomed to haunt a virtual world? A program? Or something more? Was she a player, stuck with a gaming device to her head.. forced to play in this endless death trap? Who was.. she? What was.. the Railgun?