In a world plagued by demons, a secret order known as the "Demon Blades" has emerged. This group of highly skilled warriors, each with unique abilities, has taken it upon themselves to hunt and eliminate the demonic creatures that threaten humanity. The story follows the journey of a young orphan named Kai, who joins the Demon Blades after his village is destroyed by demons. As he learns the ways of demon slaying, he uncovers hidden truths about his own mysterious past and the origin of the demons. The deeper Kai dives into the underworld of demon-killing, the more he discovers that his fate may be tied to the very creatures he seeks to destroy.