In the reign of the Emperor Suzaku (930- 946 A.D.), various mishaps happen after a strange white rainbow in appearance in the sky over Kyoto. The Emperor orders a famous astronomer, Yasunori, to consult a certain Chinese book of secrets to calm the fear of the people. Yasunori has two disciples, Yasuna and Doman. But he desires that Yasuna succeeds him because Doman is interested only in power. Assisted by Yasunori's wife, Doman sends his follower, Akuemon, to kill Yasunori. Doman also steals the secret book and puts the blame on Yasuna and his sweetheart, Sakaki, Yasunori's adopted daughter. Sakaki commits suicide and Yasuna kills Yasunori's wife in his rage. He retrieves the secret book and sets out on a journey without destination. He meets her younger sister, Kuzunoha, with whom he falls in love at Sakaki's home town. Lord Iwakura, Yasunori's brother-in-low, advices the Court that the Crown Prince has no child and this causes tourmoils. Akuemon is summoned to catch a white female fox which is to be used for charming away the curse on the Prince. Akuemon fails to find a white female fox, but meets Yasuna who has protected the foxes. Akuemon beats Yasuna and takes Kuzunoha with him. But Yasuna is rescued by a white fox. The white fox asks his daughter to transform herself in the shape of Kuzunoha to live together with him. After that, they have a baby. When Kuzunoha escapes from Akuemon and comes to Yasuna, the female fox in the shape of Kuzunoha disappears leaving a poem (tanka) beside her sleeping baby.
—Anonymous