Was at a comrades place yesterday who is currently studying a most interesting subject - Japanese school girls ^^;
He had these up on his wall - posters which are being used in the Niigata prefecture to help discourage school girls from rolling up their skirts.
The pink poster says "By putting in more effort, you will do well for both study and (extending) your skirt length."
Hmmmm. Both look cute ^^;
The following screenshots are from a news report (which was deleted from YouTUbe ><) that covered how school girls in Niigata have the shortest skirts in Japan. This school has some bloke going around school warning the girls about their attire and asking them to roll down their skirts.
Most high schools issue a standard uniform. The length of the skirts by default extend past the knees. The short length of the skirts are achieved by rolling them up at the waist and is something that many school girls in Japan.
Folks who run schools are generally not happy about the short skirts and want them extended to default length.
The reasons they give are things like the girls getting ill from catching a cold (from wearing short skirts) and because of some incidents where some girls had their skirts cut by perverts.
The skirt on right is a standard skirt but the one he left has been developed to stop the girls from rolling up their skirts by making the whole skirt messy after a rollup attempt.
If you want to measure the futomomo (thighs) of Japanese school girls then you know what line of work you need to be in - TV ^^;
Many girls roll up their skirt because they believe that they look cuter - and then there are some girls who do it because others do it.