In the aftermath of the Sengoku Era's unification under the Toyotomi army, a dark revelation shakes Tokugawa as he learns of an evil ayakashi's claim that history had destined him to triumph over Toyotomi. Seduced by the power offered by this malevolent entity named Yasha, Tokugawa sets out on a path to claim what he believes is rightfully his, jeopardizing the life of Princess Kaguya, the key to this altered reality. Standing against Tokugawa's tyrannical ambitions is Musashi Miyamoto, a spirited youth following the path of 'Gun-do', a unique blend of swordsmanship and marksmanship, determined to thwart Tokugawa's reign and protect Princess Kaguya at all costs.