Originally uploaded by Jason In Japan.
I took this photo at a recent school assembly at my Junior High school. I think it illustrates the various skirt lengths worn by the female students.
The girl on the far right has the longest skirt and is a 7th grader - all the girls in the 7th grade wear their skirts below the knee.
The girl in the middle is a ninth grader. How can you tell? Her skirt is way above her knee and only 9th grade girls are "allowed" to wear their skirts this short. If a girl in the 8th grade or 7th grade tried to wear her skirt this short, she would get beat up according to some 9th grade girls I asked about this whole various skirt length thing.
The girl on the far left is also a 9th grader, but she's wearing her skirt at a more modest height, which is acceptable but clues the observer into the fact that she is not so much in the "popular" crowd. I guess when you're all wearing the same clothes and thus can't differentiate yourself with your fashion choices, the popular girls will still find a way to separate themsleves from the rest of the crowd.
Japan is an odd country, but a fascinating one....