The film indicates that the Chiyoko's life was linked to earthquakes: she was born during the Great Kanto Earthquake, so her birth date is September 1, 1923; She gave up her career after another great earthquake, perhaps based on the Niigata earthquake (occurred on June 16, 1964), and Chiyoko dies during another earthquake: The Western Honshu earthquake (occurred on October 6, 2000).