Asta, a boy born with no magic in a world where magic is everything, and his rival Yuno, a genius mage chosen by the legendary 4-leaf Grimoire, have together fought a number of powerful enemies to prove their power beyond adversity and aim for the top mage "Wizard King". Standing in front of Asta and Yuno, who dream of becoming the Wizard King, are the Wizard Kings from the past. Conrad Leto, Julius Novachrono's predecessor Wizard King