As a reward for saving Princess Flora, Rio gets to leave behind his life in the slums and enroll in the Royal Institute! However, the story of a seven-year-old besting an assassin draws the eyes of the adults, while the other students don't look kindly on a commoner mingling with nobles. Rio has to contend with Charles Arbor, who has fallen out of favor for failing to catch the culprit behind Princess Flora's kidnapping, as well as Alphonse, a student with sway who refuses to accept a commoner among their ranks.