The year is Kyōhō, during the rule of Tokugawa Yoshimune. The shogunate faces a financial crisis, and their last hope lies in the vast "Tokugawa Treasure" left by Ieyasu. Armed with a map revealing its location, the ninja Torajirō sets out for the untamed lands of America, where indigenous tribes and settlers struggle for dominance. There, he encounters a Native American woman with a mysterious connection to the treasure. Against the backdrop of the uncharted American continent, a hidden gold rush unfolds—a story of fortune and fate untold by history!