Reno

 is a robot boy which Atom saved from falling in an accident at the robot circus and learned that he was actually a human under desguise. He was upset about being found out, but later had to admit the truth when Atom saw him in his citizen attire.

It turned out that Reno is a orphan who was found by the Robot Circus who raised him as if he was a robot. After the plan of framming the Robot Circus failed,  was put in care of Dr. Ochanomizu who had became his legal guardian.

Reno now aspires to become a great scientist in the future and later he become responsible for the creation of Gunon.

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In the Robotania episodes, Reno played a major role by rescuing Duke Red's daughter who was being prisoner of her own hospital room, because Lamp don't wanted her to tell the truth about the supposed robot attack in her home.=====

Reno is later seem in the celebration which granted rights for robots.

Trivia
Gam was choosen as Reno's desguise, because in Magma Taishi the character Gam was himself based in Mamoru as a request of Magma, who was touched by the boy's bravery and wished a son with his looks. Considering that, it was not necessary to add Gam since he was already used as a desguise for Reno, so rather than changing gender as the popular belief says, he was replaced entirelly.
 * Considering Tezuka Star-System which each character is a sort of "actor" who appears in several series in different roles, Reno is actually Mamoru from Magma Taishi (Ambassador Magma).
 * The robot desguise which Reno does in the episode Robot Circus is actually Gam also from Magma Taishi which explain why Gam don't appeared with the robot family composed by Magma and Mol. There was no need to add Gam, since Reno basically played Gam's role with his robot desguise.