One of the central elements of your time at the academy will be your level as a teacher. It starts very low (probably E or D), and by successfully completing different tasks, it will increase from D to D+, then C, etc. Your teacher level will have a large impact on your students' progress, for example instead of receiving a +4 bonus in a skill after a lesson, it will receive +6.
In addition, the number of activity points available, the budget and many other elements depend on this level.
It therefore seems appropriate to seek to increase it as quickly as possible, which will trigger a virtuous circle. Because when you say more activity points, you mean more opportunities to raise your level. It will be necessary to do like Onizuka (GTO), and mix psychology, flirtation and violence in order to be the best teacher.