Since ancient history, there has always been war between the monsters called "Abyss" and Sykoh. Abyss are predominant creatures that prowl in their massive gatherings and attack, creatures with somewhat intelligence and vary from size to appearance.

Through prolonged conflict, it was surmised that they do not kill Sykoh due to predation since they require no nutrients from their flesh, but do so thanks to bloodlust. Therefore, despite their evolved forms, they act like animals that rejoice in the agony of others.

To combat such monsters; a new position was created. A position where Sykoh were specifically trained to kill the Abyss. This position was named "Knight."

With an introduction of a new year, the newest candidate to come upon the status of a Knight, emerges. Inoyva Risse steps forth. towards this was, as underlying threats which can vanquish his understanding of what a "Sykoh" and "Abyss" are, appear