This is the story of a time before Lightning Flash and the Black Swordsman were known by those names…

Asuna Yuuki was a girl in the ninth grade who’d never had anything to do with online games when she accidentally put on the NerveGear that fateful day.

The game master speaks.
This may be a game, but it's not something you play.
“Game Over” means you die in the real world.

Hearing this, the players are sent into a state of confusion, and pandemonium reigns in the game. One of these players is Asuna. Despite not even knowing the rules of this new world, she sets out on her journey to the floating steel castle of Aincrad, its apex not yet visible.

As she continues to live on in this world where death is always a step away, Asuna has a fateful encounter followed by a parting…

Despite being at the mercy of this strange reality, she fights on valiantly until someone appears before her: the solitary swordsman, Kirito…