One day, a woman named Chiyome Hesogakure with a child named Chinzō visits the Nohara family and claims that she is the real mother of Shinnosuke and takes him away to a Ninja Village. In the Ninja Village, the Hesogakure family has been protecting "the earth's navel" by blocking it with a pure gold stopper using the "Mononoke technique" that has been passed down from generation. If it comes off, the earth will wither, the rotation will stop, and the "tomorrow" of the world will be lost! It is up to Shinnosuke to reveal the mystery of his birth and protect the future of the earth and the "tomorrow" of his family.