Seirei Gensouki opens with Haruto Amakawa, a 20-year-old college student whose life ends in a traffic accident before he awakens in a world he does not recognize, now inhabiting the body of Rio, a young boy burdened by painful memories of his own. As Haruto’s memories and Rio’s identity begin to merge, Rio discovers that he has inherited magical power as well, but this new existence does not erase the anger that still burns inside him: the desire to take revenge on the people who murdered his mother.
Torn between two lives and two sets of memories, Rio must find a way forward while carrying both grief and purpose. His path shifts when he comes across the kidnapped princess of the Bertram Kingdom and rescues her without hesitation. In gratitude, the king grants him a place at the Bertram Royal Academy, offering him a chance to begin again in a prestigious setting. But the academy is no sanctuary. As a slum-dweller surrounded by the children of nobles, Rio faces constant social pressure, sharp class divides, and the difficult task of proving himself in a place that was never meant to welcome him.