there's a book full of pictures dedicated to the freakish trends in japan. contains plenty of pictures of this kind of stuff, and other weird crap.

and yes, BC is completely wrong. friend of mine who lived in japan for almost 3 years, and whose wife is japanese, had this to say:

first of all, they're not called Kogals because they look like koalas... they're called Kogals because "ko" means child, or young. and a gal is a mature woman. so they're called Kogals because they're young girls dressing up and acting like older women. and that hasn't been in fashion for like 3 years. it's really outdated. the new thing now is to look as white as possible. ghastly white.