Tetsuwan Atom (1980)

Synopsis

Uran is watering a growing tulip when a time travel machine arrives from two centuries in the future, crushing down on her tulip. Rock, a time traveling detective, merges from the machine and announces that he is searching for Astro to participate on his adventure, and soon takes him and Uran in the machine, which then travels to the then-present day where the infamous surgeon, Black Jack and his assistant Pinoko are awaiting breakfast. Rock is also picking up Black Jack on his journey, and soon reveals that he is taking him and Astro to 15th century Silverland in order to save the life of Prince Sapphire, who, in a twist of irony, was injured from an earlier excursion to the past by the time traveller; at the same time, Rock was also tracking down a rogue fugitive from another time - Gor, an evil sorcerer who is plotting to usurp the throne from Sapphire and conquer all of Silverland with an army of monsters to do his bidding. The time machine arrives at the kingdom, where Astro recently stops a march of mutated monsters attacking the guard. With the client under his disposal, Black Jack insists that he be isolated and will not operate until he is offered the key to the treasury vault. Midday through his progress, Black Jack discovers that the Prince was actually a princess all along. No sooner did Gor returned to the castle to seize the throne room that he saw Black Jack finishing his client. After the doctor reveals the truth that he kept his word but would not operate on the princess, Astro goes into battle with the sorcerer's monsters for one final conflict. Rock, who had disguised himself as Black Jack, finally captures and unmask the villain, who turns out to be Osamu Tezuka messing up his own mythology. Black Jack, after a worthwhile operation intent on reviving Sapphire, with his acknowledgement, lets her expose the truth of her secret life to her kingdom.

(Source: Wikipedia)