The Japanese occupation of Manchuria promised many opportunities for young scientists who want to utilize this colony. Ishii Shiro seized the occasion, and with funding from the War Ministry of Imperial Japan, he founded Unit 731, a biological and chemical warfare research and development. He recruited the brightest minds from Japan to conduct human experiments, developed bubonic plague bombs, and tested biological and chemical weapons.
Within a few years, he rapidly climbed the ranks, going from Captain to General for the Imperial Japanese Army. His impact and power overshadowed his European counterpart, Josef Mengele.

After the war, he faked his death, but the CIA was able to locate him. However, he negotiated immunity and was never brought to justice. Ishii Shiro: Josef Mengele of the East is a biography based on declassified documents found in the National Archives and Records Administration. These are documents from the CIA, Far East Asia Command Center, U.S. Naval Operations, Khabarovsk War Crimes Trial, and documents that survived by chance in Tokyo.