What you see below are not see-thru skirts. They are actually prints on the skirts to make it look as if the panties are visible and these are the current rage in Japan. They'll be the rage here in the USA soon.
What I don't get is why the prints are of such ugly butts. If they have to wear that stupid fashion, they should at leat come to EF and use the Avatars of half the guys here, it would be much more pleasing for the eyes than the ones there.