Japanese junior and senior high schools are famous for their strict dress codes which are often referred as “black kosoku(school rules)”. Not only do most schools have uniforms, they also have rules for hairstyles.
My school didn’t allow skirts to be shorter than the knees and even specified in what direction should quilt pin should be.
Often times these rules can turn into discrimination. Many schools only allow black straight hair, prohibiting students from dyeing their hair. There are many cases where non-Japanese or half-Japanese students are forced to dye their hair black. If dyeing their hair was against the rule, why do these students have to dye them black?
Moreover, Japanese people themselves have diverse appearances. I have personally seen 100% Japanese people with light brown hair. I was also born with wavy hair. Fortunately, my school didn’t force me to change my natural born hairstyle, (but did force other students to submit documents proving that their hair is natural). It’s time for Japanese teachers to admit that Japanese people are diverse and appreciate the differences.

Japanese school rules regarding the students appearance have multiple flaws and is violating human rights of underaged students. What students do with their appearance has no connection to their academic performances.