Tensai Daini Ouji wa Hikikomoritai: "Gokutsubushi" no Mujikaku Musou

Neet van Avadora, the second prince of the great nation of Astoria, is a homebody who loves nothing more than staying indoors. After cutting himself off from the outside world for years to devote himself to magical research, he has, without even realizing it, grown into a true prodigy of magic. One day, however, under orders from his father the king, Neet is forced, much against his will, to enroll in the Magic Academy. There, he gradually begins to enjoy student life, blessed with quirky but kind friends. But because of his overwhelming magical talent, he constantly finds himself caught up in one troublesome incident after another...!? Meanwhile, Alex, the first prince, and the very cause of Neet's growth into an unknowing genius, sets a certain "plan" into motion. This plan will spark a great incident, one that will change not only Neet's fate, but also the fate of the entire kingdom of Astoria... (Source: AlphaPolis, translated)