Ever since the Dragons became a threat to the human race, hunters have been hunting them down for the rewards of killing them. But this is by no means an easy task. Only those able to transcend the limits of the human condition are able to stand up to the mighty winged creatures. Ragna, a relatively weak young man, teams up with Léonica, an exceptional hunter, who has already eliminated more Dragons than anyone. Only, following a tragic event, Ragna finds himself alone, driven by an insatiable thirst for revenge. Desperate to face and crush his enemies, he decides to team up with Crimson, a dark being who shares the same motivations as him: to eliminate the dragon monarchs for good..