Kael Michihiro was a normal person that could be found anywhere But all that changed when he turned 10 years old when he got memories from his previous life about the world he lived in.
At first he will avoid all canon events and contact as far away from the supernatural as possible
But all of this changed when he got a talking book called "Ars" which called himself one of the strongest Grimoire ever created.
Without Kael realizing it, his meeting with Ars would change his life forever

(Semi SI-OC with some crossover elements)
An: I'm new to writing fanfic so suggestions and responses are quite useful.
and I will use the LN version because it better conveys the DxD verse as a whole than the anime adaptation version