Seen today:

I always laugh whenever people try to do a semantic or syntactic approach to defining those Japanese age/gender-based genres. Shounen series have fighting! Shoujo has boys and kissing! Josei is mature! Seinen has lots of sex and violence! These can get really asinine when people start thinking things like Chobits is a shoujo series because Clamp wrote it and it has relationships and stuff.

Not to mention the frilly dresses, right?

I have just one thing to add: the "people" who came up with this 2x2 matrix are Japanese creators. Stores in Akihabara have these categories etched on plastic cards and attached to shelves of manga. Unfortunately, I don't have any pictures because stores uniformly prohibit photography, but trust me. And the funniest thing is, a gaijin can tell with one glance which pile of manga belongs to which category. Authors on the average conform to conventions, and it's just the fact.