Wise Man's Grandchild

Kenja no Mago (賢者の孫, lit. "The Sage's Grandson") is a Japanese light novel series written by Tsuyoshi Yoshioka and illustrated by Seiji Kikuchi. It began serialization online in January 2015 on the user-generated novel publishing website Shōsetsuka ni Narō. It was acquired by Enterbrain, who have published six volumes since July 2015 under their Famitsu Bunko imprint. A manga adaptation by Shunsuke Ogata began serialization on Kadokawa Shoten's Young Ace Up website from March 2016. It has been collected in four tankōbon volumes. An anime adaptation has been announced.

Plot
A young man who had surely died in an accident, was reborn in another world as a baby! After that, he was picked up by the patriot hero "Sage" Merlin Wolford and was given the name Shin. He was raised as a grandson by Merlin and soaked up Merlin's teachings earning him some shocking power however, when he became 15 his grandfather Merlin said: "I forgot to teach him common sense"!

An "abnormal" boy's unconventional other world fantasy life starts here!!