User blog comment:Qunow/Sword Art Online II 2014 Activated/@comment-72.171.24.125-20140112030054/@comment-1173941-20140112032521

Sinon hasn't really been shown to "Like" him in the same way the other girls do. At best she admires him, and likes to tease the other girls here and there.

That being said, yeah, the other girls are sort of into him for one reason or another. I would imagine that logically, Rika and Suguha would be taking everything the worst, given that they're more matured, and had very serious feelings for Kirito. In my opinion, Keiko seemed more like a crush, or something like that, and in her side-story she saw him as a sort of brother-figure. Though, it seems later on she grew attached.

Either way, I can write a whole essay about their relationship with Kirito, but it's rather annoying, considering that most of these characters are literally defined by this relationship. Sinon is probably the first girl introduced, who isn't defined by her relationship to Kirito.