Dr. James Bowen as an American scientist working at a hospital in Hiroshima in 1965. A former US Army scientist, Dr. Bowen was involved in the Manhattan Project and filled with remorse over the suffering of the Japanese people. As a result he dedicated his life to the study of the long-term effects of radiation poisoning, in the hopes of easing the pain of Hiroshima survivors. When a strange boy was discovered by his colleague Dr. Sueko Togami, Bowen was shocked that the child remained alive despite having absorbed massive amounts of radiation from the Hiroshima blast.
He, Sueko and their fellow scientist Dr. Yuzo Kawaji all thought that study of the boy could yield beneficial treatments for radiation poisoning. However the boy's rapid growth as a side-effect of the radiation he had absorbed meant that the hospital could no longer take care of him, and the boy, revealed as none other than Frankenstein by German scientist Dr. Liesendorf, escaped during Kawaji's attempt to dissect him. Bowen and Sueko did all they could to prevent the JSDF from killing Frankenstein, who was wrongfully blamed for various attacks actually committed by the monster Baragon.
Eventually, even though Frankenstein's innocence was proved when Baragon showed himself, the now giant boy was killed in battle with the monster when an earthquake swallowed up both of them. However Frankenstein's severed and still-living hand remained. Bowen turned his research over to a colleague, Paul Stewart, and left Japan to return to the States with Sueko whom he eventually married.