Seirei Gensouki

Rio grows up in the slums of the Beltrum Kingdom with one goal: find the people responsible for his mother's murder and take revenge. At seven years old, memories suddenly awaken inside him from Haruto Amakawa, a Japanese university student who died in an accident, merging two lives within one child and revealing unusual magical potential. After Rio helps rescue a kidnapped princess, the king rewards him with admission to the Royal Academy attended by noble children. Instead of an easy new beginning, he faces contempt for his background and must develop his abilities largely on his own. Between Haruto's memories and Rio's painful past, a long journey begins that will reshape his identity and repeatedly force him to meet people he cannot always keep beside him.