As you all know, Celestia started a school. This was to teach advanced magic to talented unicorns.
As a lot of you may not know, Luna also started a school. This was to teach advanced magic to talented non-unicorns.
We follow a pegasus filly as she has a year of trials, shenanigans, learning, practice, more learning and working to exhaustion; but she can't complain, she applied for it after all.