It seems that Viz has that yummy Azumanga manga. Also Nerve.com gets to the bottom of the bias against bis. It seems silly to me to expect everyone to only like one sex. I mean, if you've accepted that some people like girls, and some like guys, how much of a stretch can it be to think that some people like both. It seems that human variety is infinitely flexible, but the human perception of that variety can be pretty narrow.