Manga Kenja no Mago

In the modern world, in the course of a terrible car accident, a lonely person dies ... It would seem that nothing unusual, but he was reborn in a parallel world! Here he is rescued by a brilliant sage named Merlin, who brings him up as Sheena Walford. Here the guy is trained in magic and martial arts, which should help him kill the monsters terrorizing this world. He thinks all the time that he is constantly remembering his past life. After Shin turns 15, he decides to go on a journey to explore the world outside the forest where he is going to exterminate all the monsters. However, despite all the training, it seems like Merlin completely forgot to teach Shin common sense. This is how his amazing adventures in the new world will begin.