In an ancient era filled with myths and magic, a timid boy named Jun Tendo finds himself transported back in time to the Heian period of Japan. While navigating this unfamiliar world, Jun discovers he is destined to harness the power of a legendary dragon to end a centuries-old war between humans and the monstrous oni. With guidance from a wise monk named Gen'un and the support of the courageous Mizuha, Jun begins to unlock his potential and learn the ways of a warrior. As he struggles to accept his new role, he must also grapple with conflicting emotions and the weight of the enormous responsibility placed upon him.

Jun's journey is fraught with peril as he faces formidable enemies and uncovers dark secrets about the true nature of the conflict. Each encounter tests his growing strength and determination. The once timid boy slowly transforms into a resolute hero capable of extraordinary feats. Along the way, Jun forms deep bonds with his allies, discovers hidden power within himself, and gradually inches closer to fulfilling his destiny. The narrative weaves through a tapestry of intense battles and heartfelt moments, presenting an epic tale of self-discovery, bravery, and the timeless struggle between good and evil.