In a land of dragons, where citizens called breeders tame their dragon pals. Races of dragons are born from breeders who are given a Seikoku: a dragon star-shape brand. Learning to ride and tame dragons comes easy to most students at Ansarivan Dragonar Academy—except for Ash Blake, a first-year student who is known by his classmates as the "problem child." His dragon has never appeared. Despite his unfashionably large star-shaped brand that marks him as a future dragon master, he has nothing to show for it. Until now, that is. One fateful day, while challenging a princess, Silvia Lautreamont, to a dragon race, Ash's dragon awakes in full glory, but appears different than any dragon ever seen before—in the form of a beautiful girl!—naming her Eco. What's more, Ash soon discovers that this new dragon has attitude to spare, as she promptly informs him that she is the master, and he, the servant. Ash's problems with dragon riding have only just begun.