Ten days have passed since Aaron and the group returned to the academy.
Once Aaron received the rewards, he pretty much immersed himself in increasing his level, unless there was an important class or during other activities.
In these ten days, he improved vastly and even reached level 150, which is the border of Rank-2.
In this process of improving his level, some skills also improved a bit, not because he used SPs on them but because of the accumulated skill experience over time.
Improving this way was long and arduous. So, many would use SPs to increase their Skill Rank, but with what he came to learn, wasting SPs on skills that can be easily improved by using them continuously is just a waste of resources.
They need to be saved as much as possible to improve the skills that can't be improved easily by usage, especially since he came to know that Rank 9 is not the highest skill rank. There is Bronze Rank above it, and with Silver and Gold Ranks above Bronze.