A brief description of the The Irregular of the manga Royal Academy of Magic:

A world in which magic can only be used by people born into a noble family.
Although he was a commoner, Ars possessed a great magical talent, he was called “Cursed Blood” and was forced to lead an oppressed life.
He was expelled from the family home at a very young age and spent ten years training to be a magician. At the age of 15, Ars is invited to enter the magic academy to become an “official magician.”
When he arrived at the academy gates, a group of very low-level nobles were waiting for him. (This is silly. This naive thinking will not work in real battles.)
Ars, enrolled in an academy full of nobles, begins an extraordinary life as the only “ordinary person” in the academy.