just to get this out of the way before more people come in thinking kirito is a girl or has a girl character: his character is MALE, but it has very feminine looks such as long hair and eyelashes, due to a glitch that occurs every so many millions of players. this glitch can also occur if the player's brainwaves are misread during startup.
no i havent seen GGO, but I did extensive research months ago when I finished ALO and was curious about GGO, if you doubt what Im saying google it
long story short, there is a glitch every so many millions of players, and Kirito happened to get the glitch, his character is male but has feminine features (no i havent seen ggo, but i did extensive research months before it came out)
tagging you so you can read that too, just wanted to clear it up for you both
Oh I love Yui XD (we actually named our friends after SAO characters, Im Asuna, my friend is Kirito my other friend is Sachi, is Ageil XD and I think was Klein (or maybe fuzed-ice was klein and evan was kirito.. idr XD)