Dr. Tenma

When Tenma's nine-year-old son Tobio dies in a car accident, he decides to recreate him as an invincible robot.[2] After living happily for a while with the child robot, Tenma realizes that an artificial child can not replace his son, particularly when he acknowledges that the robot will not grow like a normal child. So, he sells the robot to Hamegg, a robot salesman. The robot eventually ends up performing in a circus. It is here where he is found and adopted by Professor Ochanomizu, who turns him into Astro Boy.

Tenma realizes that Astro is amazing and, even though his affection towards the robot begins to return, he knows he can never make amends for his behavior. Still, he helps Astro frequently. He builds robotic parents for Astro, enhances Astro's power to one million horsepower (700 MW) when he fights Pluto, rescues Astro from a Cleopatra robot, and rebuilds Astro after he is destroyed while trying to protect Blue Knight.

In the 1960 television series, Dr. Tenma (having been named Dr. Boyton in the English dub) was the leader of the Institute of Science, who is first introduced in episode 1. When his son, Tobio Tenma (Aster Boyton in the dub), had been killed in a car crash, he was there to see what had happened; having become heartbroken due to the loss of his son, he carried his lifeless body away from the scene of the collision. Some time later, grief drives him insane; he gets the idea of creating a robot in the likeness of his son and has every member of the Institute of Science turn their work towards its creation. The other Institute members comply with his wishes (aware that his sanity is deteriorating), and over the course of a year, his creation is assembled. Dubbing his new robot Astro Boy (Atom in the original), he brings him to life and takes him home to live as his new son. However, as the years go on, Dr. Boyton comes to realize that Astro can never replace his son. Soon afterwards, he sells Astro to "The Great Cacciatore" (Hamegg in the original) without a care in the world. He is not seen again until episode 97, which marks his last appearance in the series. It has been suggested that Tenma has either been institutionalized or committed suicide.

Doctor Tenma, as he appeared in the 1980 television series

In the 1980 anime series, Tenma (again localized as Dr. Boynton in the English versions) does not really reject Astro. Instead, he dismisses him for causing a mess at a boat dinner, after reminding him he was a robot. Astro then gets kidnapped by corrupt circus ringmaster Hamegg, while Tenma tries to get Astro back. The circus is not as harsh and Hamegg not as evil as in the original manga version. Professor Ochanomizu, who came to visit the circus, notices Astro and manages to trick Hamegg into releasing the child robot with the assistance of Kathy, a performer in the circus who showed compassion towards Astro.

In the 2003 series, Tenma, voiced by Dorian Harewood in the English dubbed version, takes the role of the main antagonist. He abandons both Astro and the Ministry in a fit of insanity, after Astro rebels against Tenma's cold behavior in destroying old robots. Later, when Tenma witnesses Astro's heroics, he begins to believe that Astro will be a Messiah figure. He believes that Astro will lead robots to equal standing with humans or he will help them overthrow humans. (The latter belief gradually takes over as the series progresses.)

Prior to Astro's first battle with Atlas, Tenma constantly calls Astro "Toby", the dead son he was supposed to replace. He only recognizes him as a separate entity once Astro corrects him.

It soon becomes apparent to Tenma that he himself cannot keep up with Astro due to his humanity. So, in order to keep up with Astro, he builds a robot to spearhead Astro's development. This robot is appropriately named "Shadow", and is eventually revealed to be a robot double of Tenma himself.

In the second-to-last episode of the 2003 series, Astro is very badly damaged and Tenma rebuilds him, but deletes his previous memories so that Astro doesn't remember he's a robot or 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, but is saved by Astro, who forgives him. Afterwards, Tenma wishes he never shut him down in the first place, and that he still loves him.

The series ends with Tenma admitting that he was never fit to be his father, after which he is arrested. The final image of Tenma is of him in a jail cell, holding a photograph of his human son Tobio and a photograph of his robotic son Astro.

In the 2009 CGI-animated feature film adaptation, Tenma, who is voiced by actor Nicolas Cage, creates Astro Boy after his son Tobio (Toby) is killed in a robot testing accident.[3] (Tenma accidentally locks Tobio in the chamber with an experimental law enforcement machine named Peacekeeper.)

Tenma, with the assistance of Doctor Elefun (Dr. O' Shay), creates a robot duplicate of Toby. He outfits the robot with advanced defense capabilities so that he can't be harmed. Then, he copies Tobio's memories into the robot, hoping the robot will be just like his real son. Tenma begins to feel that this robot duplicate is acting strangely, such as when it thinks it feels weird. When he realizes that the robot is not really Tobio, he rejects him.

After the robot runs away, he is captured for the power source that Tenma used on him. It is to be extracted from him and put into the Peacekeeper. The robot encourages this decision, accepting that he could never live up to Tenma's expectations. Tenma, however, refuses to have the robot deactivated, acknowledging Astro is his son.

Tenma is non-villainous and less mad in the film. Instead, his personality is similar to that of the original manga (although this film version takes considerable liberties with the source material overall). In the film, he reacts similarly as in the manga, realizing that Astro is not his son and rejecting him. However, he does not sell him to Hamegg. The major difference between the character of Tenma in the film and in other versions of Astro Boy is that Tenma comes to accept Astro. Additionally, this version gives him the first name of "Bill".