After the demon lord Hadlar's first defeat, monsters settle into peace on Dermline Island, where the human boy Dai grows up dreaming of a heroism the quiet island never gives him a chance to prove. When Hadlar returns and kills his mentor Avan in the opening episodes, Dai discovers a strange mark and a sudden power that let him stand against the revived demon lord, setting him on the road with fellow students Popp and Maam. This 1991 TV series is the original Adventure of Dai anime, remade in 2020, and is remembered across Latin America and Brazil under Dai's classic dub name, Fly.