the rude shoes

I got to school later than usual the other day, and saw a few teachers at the entrance checking the students' shoe lockers. In Japan students change into their indoor shoes at the entrance and store their outdoor shoes in small lockers. I asked one of the English teachers what they were doing, and she said that they were checking empty shoe lockers against that morning's role call. But she was carrying a big empty cardboard box and said that another job was to check that students were wearing their shoes properly and weren't squashing down the heal to wear them like slides. She said, "It's rude, so we collect the rude shoes and take them to the staff room." This is the little-known battle that Japanese junior high school teachers are fighting every morning... the battle against The Rude Shoes...