This OVA uncovers the truth about Gau's relationship with his adoptive sister and the concealed realities of shadow skill. Each year, Gau and Elle pay their respects at their parents' gravesite to demonstrate his progress as a Sevalle warrior. Nonetheless, danger looms in the background, ready to pounce at any given moment. While on their journey, the group's familial bonds and expertise will be challenged by several adversaries. Gau will have to face off against his own sister to refine his skills and vanquish his mightiest opponent. Though the battles will be arduous, Gau's unwavering conviction and rigorous training will lead him to triumph.