Board Thread:Questions and Answers/@comment-24.99.111.181-20150102193131/@comment-6604690-20150104011328

There are two theories for this:

1. Kirito played SAO for a long time, so its data of Kirito's playtime got transferred when converted to ALO and to GGO. Thus, the system rewarded him with that "female" avatar.

2. The system got "confused" when scanning Kirito's appearance, and ended up with a male avatar that looks like a girl. GGO wasn't the first time Kirito was described a girl by other people though. (ex. in Ep. 1, Klein commented that Kirito's real face looked like a girl.)