Manga

Kenja no Mago (賢者の孫 lit. Magi's Grandson) is a Japanese novel series written by Yoshioka Tsuyoshi and illustrated by Kikuchi Seiji firstly relesed as a web novel. Individual volumes have been serialized as a light novel in Enterbrain since July 30, 2015. The novel was later serialized as a fantasy manga illustrated by Ogata Shunsuke in the magazine Young Ace Up (Kadokawa). As of November 30, 2017 there are 7 volumes of novel, 1 extra volume and 5 volume for the manga.

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!!

(Source: Translated from official synopsis)

About
The story centers around Shin Walford, who died after being hit by a truck and was reincarnated as an orphan in another world. A Magi found him along the corpses of people on a wrecked carriage. Due to his unique way of upbringing under the tutelage of the Magi, Guru, a previous General, and the other friends of the Mag. Shin later realized at his 15th birthday, he lacked the common sense for the new world

Trivia

 * Japanese Comic Ranked 21, April 24-30.
 * Japanese Comic Ranked 12, July 24-30.
 * Japanese Comic Ranked 10, October 23-29.