Wise Man’s Grandchild (Light Novel)

When a powerful wizard and sage, who has saved the world from calamity many times, comes upon a baby whom they adopt and name Shin. The baby is actually a man from our world reincarnated into their world. The sage raises Shin, separated from the rest of society, and teaches him in the ways of magic. It is only when Shin turns 15 years old and sets out on his own journey that the sage remembers that he forgot to teach Shin the common sense and ways of this particular world. And so, Shin goes the capital of the Alsheid Kingdom to enroll in the capital's magic academy.