Seirei Gensouki: Spirit Chronicles

Amakawa Haruto, a young man who died five years ago before reuniting with his childhood friend, Rio is a boy living in the slums whose mother was murdered when he was five. Earth and another world. Two people with completely different backgrounds and values. For some reason, the memories and personality of Haruto who should've died are resurrected in Rio's body. As the two are confused over their memories and personalities fusing together, Rio decides to live in this new world. Along with Haruto's memories, Rio awakens an unknown "special power," and it seems that if he uses it well, he can live a better life. However, before that, Rio encounters a kidnapping of the princess from his Bertram Kingdom, and after saving her, he is given a scholarship at the Royal Academy, a school for the rich and powerful. Being in this school as a poor orphan in a world of nobility turns out to be an extremely detestable place.