"Who cares about Japan's history? It has nothing to do with my existence." With these remarks, Saburou, a carefree high school student, is unceremoniously transported back in time to the Sengoku Era, landing in front of the great general Nobunaga Oda. Nobunaga, on the run from his retainers and in need of rest owing to his weakness, begs Saburou to stand in for him, as the two have an eerie likeness. Although Saburou is still perplexed by his surroundings, Nobunaga rushes to supply the youngster with the essential goods to establish that he is the genuine feudal ruler and flees. Now a stand-in for someone he doesn't even know anything about—though his present experiences and expertise are certain to help him.