Kazuto Kirigaya (aka Kirito) has survived the death game of Aincrad masterminded by Akihiko Kayaba, programmer of Sword Art Online, and made it back to the real world. Unfortunately, the same cannot be said for Asuna Yuuki (aka Asuna the Flash), the girl Kirito fell in love with in the game world and who has yet to awaken from her seemingly endless slumber.
As his sister Suguha sadly looks on, Kazuto continues to visit Asuna in the hospital in the hope of finding answers... But one day, the answers suddenly find him in the form of a man who claims to be Asuna's fiance?! With him, the man brings an in-game screenshot of someone who looks a lot like Asuna being held captive! Now Kirito must dive into an all-new VRMMORPG, Alfheim Online, to bring Asuna home!