Rio, an orphan surviving alone in the Bertram Kingdom, discovers at age seven that he carries the memories of Haruto Amakawa, a Japanese university student reborn as him after death. When his awakened magic lets him rescue two kidnapped princesses, the feat earns him a place at the Royal Academy despite his commoner blood. This light novel follows Rio's early days there alongside his one friend, the teacher Celia Claire, as he investigates his mother's murder and studies the kingdom's spirit magic.