The empire that had stood for thousands of years fell apart. The orphan of the royal family is hunted by a powerful dragon knight. The Demon Flayer, who stands at the top of the magic world, is forced to duel with the Black Dragon King. Defeated, he used the method of Nirvana to gain new life. When the sealed memory was broken from the 17-year-old Rafa, he found that he had become a trainee knight with a bright future.