After a fishing boat is attacked, the sole surviving crew member realizes it is none other than a resurrected Godzilla. However, efforts to bring the story to light are suppressed by the Japanese government amid growing political tensions between the United States and the Soviet Union, who are both willing to bomb Japan to stop the monster.
After the previous Godzilla attack, a miniature arms race ensues to collect his cells. Concerned over Godzilla's possible return, the Japanese government uses the cells to create a new bio-weapon, ANEB (Anti-Nuclear Energy Bacteria). They seeks the aid of geneticist Genshiro Shiragami, who's experiments result in a new mutation.
JSDF pilot Akane has a fateful encounter when a new Godzilla emerges in Tateyama. As a countermeasure, a cyborg named Kiryu is constructed from the remains of the original. The machine is discovered to harbor the restless soul of the original monster as Akane must learn to find value in her own life as well.
