The seemingly eternal cat-and-mouse battle has ended, and now everyone is living peacefully. One day, an Eto-musume named Na-tan appears, to the puzzlement of the 12 signs, and to the unreserved delight of Nya-tan. Meanwhile, Chu-tan also appears and warns of a looming disaster. "The seal has been broken." Who is this mysterious Eto-musume Na-tan? What in the world is the deity that has awoken beneath the seal?