Board Thread:Questions and Answers/@comment-5105419-20131208080434/@comment-1173941-20131212164654

I think that something worth noting, is that neither Asuna nor her brother were Hard core gamers. Asuna was a young impresionable mind who didn't want to "lose" to the world, which was the only reason she leveled up, and ended up meeting Kirito. She was able to adapt.

However, we know nothing about Koichirou. We know that he never got to play SAO due to some kind of buisness trip he had to take at the last minute, and we can assume he never played ALO after that, with Asuna. So it's possible he wasn't a gamer in the least bit at all, and maybe even bought SAO on a complete whim.

Point is, that Kirito likely would not have met Koichirou, at least not for several floors, by chance. And that's assuming that Koichirou actually tried to level up, and not just stay on the first floor forever...