Abstract:
Dragons are born in twins set, one dominant while the other is submissive.
One can't survive without the other, the dominants are sent to military schools, they'll spend most of their life-controlling their Dragon side.
While the other half goes to Dragon Academy, they'll learn how to cope with being submissive, they are categorized into littles, pets, or simply submissive.
The older dominant would meet them there, teach them how to shift, protect them from all dangers, and finally claim them as theirs forever.