Vulkay, the ten-year-old main protagonist, debuts in the initial episode "Come Forth! My Disk Monster!". Hailing from the planet Aernia – home to the nations Volculm (Fogo), Zylan (Água), Elvan (Floresta), and Aelum (Nuvens) – he trains as a cadet at HEROES Academy. There, cadets collect Battle Disks to summon powerful monsters crucial for planetary defense.

Teaming up with fellow hero apprentices, Vulkay strives to master Battle Disk power, determined to thwart the antagonist Orbiton's quest for galactic domination. His core mission is defending Aernia against dark forces bent on universal control. While Sophie harbors feelings for Vulkay, he remains unaware of her affection. Despite this obliviousness, he exhibits protectiveness when his rival Gael interacts closely with Sophie.

Gael serves as both rival and ally to Vulkay. Their interactions often spark clashes due to differing approaches, particularly Gael's tendency towards intellectualization. Nevertheless, they share a foundation of mutual respect and appreciation. Vulkay participates in vital missions, such as protecting Priestess Maya and infiltrating enemy mother ships. He engages in decisive battles including the resurrection of the Legendary Red Dragon and the climactic "Alma-Packed Final Showdown".

The narrative concludes with Vulkay gazing toward future cosmic adventures.