Dr. Tenma

Dr. Tenma is a recurrent character in Osamu Tezuka's Astro Boy franchise as the creator of Astro. He appears in every Astro Boy series with the exception of Little Astro Boy.


Original manga


1960s series


1980s series

1980s appearance.

In the 1980s series, Tenma received a large role in the first few episodes, however did not appear in the later ones. He is the leader of the Ministry of Science and is the father of Tobio; although he loves him dearly, he is often too caught up in his own work. After he broke his promise and fails to take Tobio to the zoo, a heartbroken Tobio rides home and dies in a tragic car accident (since boys of Tobio's age are not normally permitted to drive hover cars).

Thus, in order to replace Tobio, Tenma makes a robot duplicate named Astro Boy, although various problems arise, forcing the public to know of Astro's existence. Therefore, Tenma decides to take himself and his son on a cruise to America. After Astro continues to make mistakes, Tenma proclaims that he is not his son anymore. After he realizes his mistake, he goes back to try and find Astro, without any luck.

After that, which is the beginning of the episode, Robot Circus, Dr. Tenma would no longer appear.

It is left unexplained why Tenma never goes back to look for his robot son who is now world-famous, but he is probably too ashamed to do so and expects Dr. Elefun to look after him.

2003 series

2003 series.

In the 2003 series, Dr. Tenma is known for being a secondary villain. He is portrayed as someone who has borderline insanity: he lives far away from other people, sometimes talks to himself, doesn't trust anyone, and also has a habit of mourning over his deceased son, Tobio.

Tenma, amazed by Astro's abilities, believes that “robots are the future” and because of this makes many plans in order for robots to “take over” Metro City. He and Dr O'Shay are shown to be long-time rivals. He believes that Astro will lead the robots and eventually overthrow humans. He sets various “challenges” for Astro throughout the series, and when he finds out that he cannot progress any further, creates Shadow, however Shadow later turned against him.

Prior to Astro's first battle with Atlas, Tenma constantly calls Astro “Tobio”. He only recognizes him as a separate entity once Astro corrects him.

In the second-to-last episode of the 2003 series (Astro Reborn), Astro is very badly damaged and Tenma rebuilds him, but deletes his previous memories so that Astro doesn't remember that he's a robot and doesn't remember any of the adventures he has been on. Astro, however, rejects Tenma a third time for his cold attitude. Because of this, Tenma attempts suicide in the final episode. However, Astro forgives him, Tenma forgives Astro and all ends well.

Feature film

Dr. Tenma also appeared in the movie. Once again he created Astro to replace Toby, although this time it is because he got vaporized by the Peacekeeper. He and Dr. Elefun are on good terms this time. Also, he is opposed to President Stone.

Like all of his other appearances, Tenma originally rejects Astro - but has a change of heart when Stone brings Astro back to the surface and orders him to deactivate Astro. Prior to Astro's final battle with the Peacekeeper, Tenma wants to take Astro home again and yet the boy robot knows what he must do - destroy the Peacekeeper.

Character Development

Character Sketch by Tezuka

“Dr. Tenma was born into a long line of horseradish farmers, in the particularly unlucky year of the horse, in Gunma (“horse herd”) prefecture. Real name is Taro Uma. Graduated from the university of Nerima (“walking horse”), and though a complete dark horse, through an amazing demonstration of intellectual power rose to be the head of the ministry of science—in an area of Tokyo known as Takadanobaba, which loosely translates into a “high pasture for horses”. Among those wishing to unseat him, he is known as a real horse of a different color.”


Like many other characters, Dr. Tenma is often known by a different name in the different dubs. These include Dr. Nagayima Tenma, Dr. Boynton, Dr. Balthus, and Dr. Bill Tenma.


The word Tenma literally means heaven-horse in Japanese.

In the 1960s series, he is voiced by Hisashi Yokomori in the Japanese version and by Ray Owens in the English version.

In the 1980s series, he is voiced by Tamio Ohki in the Japanese version and by Del Lewis in the English version.

In the 2003 series, he is voiced by Shinya Owada in the Japanese version and by Dorian Harewood in the English version.

In the 2009 feature film, he is voiced by Nicolas Cage.