The third-year students lived in the third largest peak of Originveil Academy, and although the academic year had just passed with the third-year students passing the tests and entering the new level, the students had still not adjusted to the peak's environment.
The mana density and purity of every next peak students progress to are higher than the ones before, making it hard for them to just start living there without any care of anything.
It would've been fine if they were going to live there for some days, as the high concentration of mana would feel heavenly to them, but it won't be good for them in the long run, so the students had to meditate and cycle the mana in their bodies for at least a week to get used to it.