Osamu Tezuka claimed that he received inspiration for his Metropolis manga from seeing the poster for Metropolis (1927), but never actually saw the film.
Director Rintarô says that Osamu Tezuka probably wouldn't have let him make the film if Tezuka was still alive.
It was in production for 5 years.
Rock is the only character who didn't originate from the original manga. He was added to this movie to make the story more interesting to watch.
A total of 150,000 animation cells were used.