Seirei Gensouki

Haruto Amakawa is a young man who died before reuniting with his childhood friend who had disappeared five years ago. Rio is a child living in the slums of his city, wishing to avenge his mother against the people who murdered her before his eyes when he was five years old. Earth and another world, two people with two different lives and values. For reasons yet unknown, Haruto's memories and personality, which were supposed to disappear, reincarnate in Rio's body. Thus, their memories and personalities become intertwined. With Haruto's memories, Rio awakens a very special power, which would allow him to have a better life if he used it. But before that, Rio witnesses the kidnapping of the two princesses of the Kingdom of Bertram. After saving them, Rio receives permission to enroll in the Royal Academy, a school for rich and powerful people.