"Who cares about what happened in Japan's past? It has nothing to do with my life." With these words, carefree high school student Saburou finds himself abruptly hurled back in time to the Sengoku Era, landing right before the legendary general Nobunaga Oda. Nobunaga, fleeing from his retainers and seeking rest due to his frailty, begs Saburou to take his place, as the two share an uncanny resemblance. Although Saburou remains confused by his surroundings, Nobunaga quickly hands the boy the necessary items to prove he is the genuine feudal lord and makes a swift escape. Now acting as a stand-in for someone he hardly knows—though his modern experiences and knowledge are sure to help him—Saburou begins his unexpected quest to pose as the man who attempted to unite all of Japan.