Bio-Major is a powerful American joint scientific corporation, consisting of multiple companies that have joined together in order to pursue a global monopoly in the field of genetic engineering. It is suggested that Bio-Major intends to use their monopoly in order to control the world's food supply and produce powerful bio-weapons. In order to achieve this monopoly, Bio-Major resorts to illegal espionage and terrorist tactics, secretly deploying agents to other nations to sabotage other corporations and governments through bombings and armed conflicts.
Bio-Major first appear in an ambush on a group of Japanese scientists collecting G-Cell samples from the ruins of Tokyo in 1984, but they too are attacked by an elite spy from Saradia, SSS9. SSS9 steals the samples and gives them to Genshiro Shiragami, demanding under orders from the Saradian government that he use them to develop plants resistant to drought. Later, Bio-Major bomb Shiragami's laboratory in Saradia in retaliation, killing his daughter Erika.
In 1990, Bio-Major are still active, and two of their agents, John Lee and Michael Low, raid Shiragami's new laboratory on the shores of Lake Ashi to steal information about the Anti-Nuclear Energy Bacteria, but meet opposition from none other than SSS9. The Bio-Major agents fight for control over the documents, but Low is killed by Biollante, who strangles him with her tendrils. Lee later plants explosives on Mount Mihara on Oshima Island, demanding that the Japanese government hand over the ANEB that Shiragami was developing, or he will release Godzilla from his volcanic prison. Colonel Goro Gondo and Dr. Kirishima meet Lee on Oshima Island to hand over the ANEB, but their negotiations are interrupted by SSS9, who opens fire on them. Lee tries to drive away in the vehicle containing the controls for the explosives, but is killed by SSS9 with a sniper rifle. Gondo and Kirishima enter the wrecked vehicle to try and deactivate the explosives, but are too late, allowing Godzilla to be released. In the confusion, SSS9 recovers the ANEB and escapes.