Ranma ½ S04E01 - The Return Of The Hawai'ian Headmaster From Hell

The Principal is back to Furinkan high!  He has been studying education in America, but appears to have learned some odd lessons and seems insane.  He starts a dress code change, requiring buzz cuts for boys and bowl cuts for girls, unless the students can find a very specific coconut that allows them to "get out of rules free".