Neglected Royal

This is my AU. Instead of clan, there are kingdom, for example Kushina is the ruler of the Uzumaki kingdom and Minato is the ruler of the Namikaze kingdom. The natural heir is the oldest child. So what happens when someone else gets chosen to be heir of the throne? Well the eldest child is banished from the kingdom. So what happens when Menma gets the throne and Naruto gets banished? Read to find out