Every school has their own rules.
There are some rules in Japanese schools. The students are not allowed to dye their hair and keep the hair Japanese black color. They are not allowed to wear earring, either. Almost all student to wear uniforms. The students mustn't be late for school. If they are late, they can't get into the school gate because the school gate is closed. In Japan, students are not allowed to have part- time jobs because they may not concentrate on their study.
American schools have their own rules. For example, in Morton High School, students are not allowed to choose their own clothes. They must get to school and leave school on time. They must wear sports shoes in gym class. They should keep quiet in the school bus. In America, the students can have part-time jobs in their free time.