This story of this work takes place on the last day of the Earth. This long Manga is typical of Tezuka Osamu's early science fiction works.
Another human race called "Fumoon" is created as a result of nuclear tests. But no humans know this fact except Dr. Yamadano. He warns the world of the coming danger, but no one listens to him.
A war breaks out between the Republic of Star and the Uran Federation, while dark clouds of toxic gas are moving towards the Earth. The other human race ("Fumoon") already knows about the danger, so they select 50,000 kinds of animals and 500 obedient people and have them board a spaceship to leave Earth. Meanwhile, dark clouds of gas are getting closer to Earth, and doomsday now seems imminent.


Published in two volumes (volume 1:published on January 10, 1951, volume 2:Chapter of Dark Space, published on February 10, 1951)

This work is the last book that Tezuka Osamu wrote for his publisher in Osaka, and the last book of a series of science fiction works that he wrote in the earlier stages of his career, following "Lost World" (1948) and "Metropolis" (1949).
This work is unique in that more than 20 characters, including Detective Higeoyaji, his nephew Kenichi and Rock, who is a newspaper reporter, play important roles. The story is set in Japan, the Republic of Star and the Uran Federation. There is a well-known anecdote about this work: originally, Tezuka Osamu wrote a 700-page (some say a 1000-page) manuscript but later reluctantly made the story shorter by cutting about 400 pages because the editor thought 700 pages was too long for a book