Responses
I think someone speculated that he might just be leaving their class rather than the school altogether. If he is a substitute for another class he still has the opportunity. Or maybe he is planning to ambush Azusa and have his way with him before leaving.
How can a substitute teacher who has finished his time play the game? Maybe he gets such poor marks in classroom management and not engaging the students that they send him to observe the class for a few more months? I mean, look at his students:
http://iweb6.mangapicgallery.com/r/newpiclink/caste_heaven/12/8558392b8d33324def1ef7d897fdbf98.jpeg
One girl is crying and everyone else is ignoring him. I assume class is over, but still--usually people say goodbye even if they don't like the student teacher. They look like he bores them to death.