Said to be humanity's natural enemy, formidable dragons that belong to an ancient bloodline roam the world. Only two ways prove effective to kill a dragon: freezing their blood with silverine—an aura that comes from silver weapons—or letting their bodies be incinerated by sunlight.

Young hunter prodigy Leonica is accompanied by her close friend Ragna, who appears to lack the skills necessary in their profession. Moreover, many shun Ragna, considering him cursed because dragons always seem to attack him and slaughter his close ones. Nevertheless, Leonica sees potential in Ragna and gladly partners up with him. Likewise, Ragna feels certain that Leonica is immune to his misfortune thanks to her incredible strength.

His confidence is shaken, however, when Ragna dreams of Leonica's death, believing this to be a prophecy. As the destined day arrives, he comes face-to-face with his future self, who bestows him enormous power and memories from the future to ensure Leonica's safety. In order to succeed, Ragna must join forces with a mysterious figure known as Crimson and eradicate all dragons for good.

Ragna Crimson was released on Blu-ray in two collected sets by King Records from February 21, 2024, to June 5, 2024.