January 7, 1970
Appeared in "Form Shonen Champion" (Akita Shoten Publishing Co., Ltd.) as a series of complete stories

Once upon a time, there lived twin sisters, Princess Tomoe and Princess Fushimi. Princess Tomoe was plain but sweet at heart, while Princess Fushimi had a beautiful face but was cruel by nature. Both of them loved Honjo Tadamichi, the head of a powerful clan, but Tadamichi chose Princess Tomoe for his wife. With a bitter grudge against her sister, Princess Fushimi tricks Tadamichi into killing Princess Tomoe. As a result, however, Princess Fushimi takes on Princess Tomoe's face, and she goes insane and dies. There remains only the mask of Princess Tomoe...Tezuka Osamu is requested to design a toy using the mask of Princess Tomoe from the above legend, and although he is reluctant, he agrees to do it. But an ominous incident occurs as Tezuka expected, and the mask of Tomoe...