After the match ended Leon said goodbye to Valery and left the arena. After leaving the arena Leon went towards his room in the academy where he rarely visits.
Leon is a C+ rank hunter so he rarely stays in the academy and spent most of his time outside doing different kinds of missions, or clearing dungeons to gather resources for himself.
The rules of the academy will be quite lax on you after you become a C rank hunter.
Unlike other students who will have to attend classes if they are not doing a mission or have an emergency, you don't need to bother about these things after reaching C rank.
You will be allowed to skip classes since they also knew there is very little a C rank hunter can gain after going into classes.
But this thing is only limited to the students who reached the C rank. And it is not easy to reach C rank while you are still attending the academy.