The Sage's Grandson

A boy named Shin, who possessed memories from his previous life, was taken in by an old man called the "Sage" by people around the world. The sage had mastered all forms of magic and saved humanity from disaster numerous times. Raised as the grandson of the sage who had retired from the world to live in seclusion, Shin absorbed all of the sage's techniques and grew to the point where he could even develop his own magic, thanks to his previous life's memories. Then, when Shin turned 15 and was about to become independent, his grandfather said: "Oh, I forgot to teach you common sense." To teach his grandson, who had grown in an unconventional manner, the level of ordinary people, common sense of society, and how to interact with others, the sage enrolls him in the "Aalsheid Advanced Magic Academy" located in the capital of the Aalsheid Kingdom.