Many people know that Japanese public schools require children to wear a school uniform. If you have ever been on a train in Japan when school lets out, you've experienced the throngs of uniformed adolescents that trudge in, giving you a distinct experience of Japanese group behavior.
Many westerners notice that the girl's uniforms resemble sailor uniforms; while less obvious is that many of the boy's school uniforms are military tunics reminiscent of 19th Prussia. The uniforms are different from school to school, and it's not an exaggeration to say that some kids choose their high school based on how fashionable the school's uniform is.
Here is an excellent article on the the development of the Japanese school uniforms.