Ouritsu Mahou Gakuen no Saikasei: Hikongai Agari no Saikyou Mahoushi, Kizoku Darake no Gakuen de Musou Suru

A child from the slums discovers the ability to use magic, a power reserved for the chosen few. A sorcerer named Genos Willzard discovers this talent and takes the child under his wing, training him into a top assassin. Eventually, Genos gives him a new mission: to enroll at the Magic Academy.