After the havoc caused by Godzilla in the mid-1980's in Tokyo, Japan sought to protect themselves in case the beast were to return. From the ghost city's remains, they pulled from the rubble several torn pieces of skin from the nuclear giant. Over the years the samples were tried and studied, birthing from their endless genes the Anti-nuclear Energy Bacteria, a Biological weapon that would be cancerous to the leviathan and theoretically kill it.

One of these scientists that devoted his life to the research of the Godzilla cells was named Dr. Shiragami. Shiragami wished only to combine the genetic material with various species of plants, in order to turn the arid wasteland of the country Saradia into fruitful plains of genetically perfected grain. Unfortunately, other nations would not approve of this sudden increase of wealth in the agricultural sector by a country that had become dependent on outside food imports, and so the lab was bombed. One of those caught in the blast was Dr. Shiragami's daughter, Erika. This act of terrorism that claimed his only child's life was graving to the man, so much, in fact, that he went as far as to splice his daughter's DNA with that of a rose, in hopes of preserving her. When the plants began to die, Shiragami injected them with a few scrapes of Godzilla's cells, thereby giving the plant's eternal life through the accelerated cell regernation. However, the doctor stumbled into the ignorance of science. Days later, the flower mutated and escaped, after killing an American bio agent sent to infiltrate Shiragami's lab, to the water of Lake Ashino. The next day, onlookers witnessed the fanged rose tower above the clear waters, baring its teeth and swamping her grounds with gnawing vines.

Soon after the rise of Biollante, Godzilla emerged from his volcanic tomb and instinctively heading to the Lake to face this modern clone of himself. The war raged that night as Biollante, still clinging to the human spirit within, fought only defensively against its attacker, which lead to its defeat. Godzilla was relentless, as his ray racked the body of Biollante and set the plant on fire. Transforming the mass of roped thrones, into a burning, mourning skyscraper. Yet, in the flames and smoke, as she dissolved away to glittering pollen, her true form evolved, crying for revenge and blood at its killer.

Some time after the war with Biollante's rose form, Godzilla waded his destruction across Japan. Finally, the leviathan was met by Japan's full army at the Wakasa plains, and it was here that Biollante returned. The seemingly immortal foe rained it spores from the heavens, and soaked into the parched earth. Soon after, the beast pulled itself from the ground, and showing the beast that lied within. Immediately she blasted forth her hellish acid and spearing tendrils, burning and ripping the monster king to bits. Though Godzilla fought back, the combined forces of Biollante and the injected Anti-nuclear Energy Bacteria were too much. His power was taxed beyond limits and the saurian was forced to retreat, as the creature waded his way to the shore. As Godzilla fell into the waves, Biollante returned to the sky, giving one last sight to her father that Erika would live forever, but trapped in the bowels of a demon.