The truth about Yui is finally revealed. This was a somewhat sad episode.

Basically Yui was an autonomous guidance counselor program of sorts that monitors and was supposedly help the players with their mental health but because Akihiko Kayaba is a dick, Yui can’t do her job. Long story short, because Asuna and Kirito are the only players that radiate joy in SAO, she sought to meet them and it all came down to this episode.
This episode was sad, almost brought me to tears, but this doesn’t compare to the Sachi arc. The Sachi arc was almost like crushing despair. My only gripe in this episode is that the reveal of Yui’s regaining of memories was done in a rather convenient manner, I was hoping for a more dramatic moment than that.
Next episode title is The Depths of Hell, looks like things are about to get serious.