Normally a person is in school until they become a 15 year old teen and get their system. After getting their system the teen then gets to be in school for 1 more year. Depending on the actions these teens take they are qualified to enter colleges suited for them.
Some colleges focus on a certain type of combat. Some colleges make it so students choose what subjects they want to study.
The no. 1 college in the world is Heavens Gate College.
The no. 2 college is Combat Master College.
The no. 3 college is Master Of Healing.
The no. 4 college is Master Of Knowledge.
The reason Heavens Gate College became no. 1 in the world is because it is on of the few colleges that gives its students the option to study any subject. Students here focus more on teamwork.