In the Manga and 2004 Series Edit
Much the same in either version, a young American man named Kelly lets Dr. Dragnet use him as a test subject for the Tetsujin Project. This division of the project involved replacing all but a human's brain with robotics. Kelly, now with the full appearance of a robot, was discarded and buried by Dragnet. He is resurrected accidentally through lightning, but suffers from headaches and sensitivity to lightning. He hunts down and and attempts to murder Dragnet and his colleague Makimura, which causes Shikishima and Otsuka to pursue him.
In the 2004 series, Kelly has a brother named Johnson, and their parents die in the bombing of Pearl Harbor. The two promise each other to go to a place full of peace, which evolves into a mutual dream to go to space. Johnson begins working as Dragnet's assistant, but following Kelly's accidental revival, he locks Johnson in a basement and takes his identity. He stays with Dragnet long enough to kill him and Professor Makimura, and after his identity is revealed, he attempts to cling to a rocket headed for space. Kelly's body breaks down in the stratosphere and he dies falling to earth. Johnson escapes sometime after and comes to take home Kelly's robotic face.
In the Emperor's Emblem manga Edit
In the 1980 Series EditIn an interesting change, Kelly's human exterior is retained, all the while having his robotic strength and powers. Not much is available on his episode, due to a lack of widespread release of the show in English. It is most likely that he might have died. He was named Kelly Martin in this series and, like Johnson as his younger sibling in the 2004 series, he has a sister named Mari.
Giant Robo OVAEdit
A humanoid cyborg who looks like Kelly (from the manga) appears briefly in "Barefoot GinRei" and the first episode of Giant Robo wherein he shots the BF member to save Dr. Shizuma. It turns out he is one of GInrei's disguises.