It had been two months since the end of the Sword Art Online (SAO) incident. Although the majority of the 6,147 surviving players have been logged out successfully, 300 of them, including Asuna, had yet to awaken for unknown reasons. Kirigaya Kazuto (Kirito), who had acquired Asuna's location from a representative of the SAO Countermeasures Division in exchange for information about the SAO incident, constantly visited her at the hospital.
During one of such visits, Asuna's father brought a man named Sugou Nobuyuki into the room. When Shouzou left the room, Nobuyuki revealed that he was going to marry Asuna the following week, while she was unable to do anything against this decision. Nobuyuki then claimed that he had every right to do so as he was in charge of RECT Progress, the company which had taken over the management of the Sword Art Online servers after the collapse of Argus, the company that released the game. The next day, Kazuto received an email from Agil (Andrew Gilbert Mills) which included a photo of what appeared to be Asuna trapped in a bird cage.
Kazuto found out from Andrew that the photo was taken by players who attempted to fly up the World Tree in ALfheim Online. After hearing more details about the game and noticing that the game was produce by RECT Progress, Kazuto decided to check the game to see if Asuna was really in it. In the game, he ended up in the Ancient Forest due to an error and met a Sylph player named Leafa, who was being threatened by three Salamander players. After hearing about Kirito's desire to go to the World Tree, Leafa offered to take him there and the two set out on their journey the next day.