The Day After

The Day After (ザ・デイ・アフター) is a short story written by Kawahara Reki, and was included as an extra in the limited Edition DVD/BR sets for the anime, volume 9.

Summary
Kirito and Asuna are doing homework together inside and Inn in Yggdrasil City. They start talking about a problem Asuna is having: sometimes she feels that she is separated from her avatar and loses control for a moment. After discussing the different possibilities, they decide to ask Yui for help. When she logs out, Asuna sees a scene outside her window, which brings memories, but those aren't hers.

The next day they talk to Yui, although she is unable to locate a problem, she proposes a solution, that it must be a player's registered information that is interfering with Asuna's gameplay. They have to end their discussion there because it was time to meet the others because they were going to face New Aincrad's 8th Floor boss, Wadjet the Flaming Serpent.

During the fight, Asuna looses control once again, but is saved by Kirito, who was warned by Yui about the phenomenon happening again. After an hour of battle, the raid party is wiped and everyone returns to the Labyrinth's entrance. Although the others want to try again, Kirito decides to leave and is followed by Asuna and Yui.

Asuna follows Kirito until he stops outside the 27th Floor. They sit on an edge and he tells her that maybe the one trying to make contact with her is from his former guild. Yui corroborates this by stating that Asuna's avatar remains attached to Kirito's old avatar. Kirito says that three minutes later, will be exactly 2 years since the time Sachi died. At that moment, Asuna has the strongest feeling of detachment and has a vision in which Sachi asks her to tell Kirito that she was happy.

The next day they prepare to face Wadjet the Flaming Serpent again, but with ten minutes remaining, Yui convinces Kirito to change his hair style, since she wants to feel more comfortable while sitting on his head.