The Noverland Empire's army led by the dragonslayer Sigbert has long been obsessed with capturing the island of Eden. Sigbert and his army have been rebuffed many times by Eden's dragon protector. On one such expedition, whether by chance or fate, Sigbert's daughter Brunhild was left behind on the island's shores.

Eden's dragon found her, cared for her, and began to raise her as a daughter. They grew to love one another, with the dragon teaching Brunhild never to hate and always forgive. But 13 years later, Sigbert finally claimed the dragon's life, and "repatriated" Brunhild to her motherland. The flames of vengeance begin to burn within Brunhild, and she must choose between her love for the dragon whom she lost or her love for the words of forgiveness that dragon spoke.

(Source: Kadokawa, translated)