A terrible race of monsters from space called the Symbiotic Legions appeared on Earth and began to collect silica in Sapporo. The silica, when properly processed by these exotic life forms, would produce enough oxygen to power a massive, flower-like organism and allow it to launch an enormous seed into space. As oxygen levels continued to increase at an alarming rate, a full assault on the Legion Flower was deemed unwise, as the resulting explosion would completely obliterate the surrounding city. Luckily, Gamera soon arrived on the scene and annihilated the flower with two scorching fireballs. The Symbiotic Legions swarmed onto Gamera, but were soon distracted and attracted to a nearby transformer, where they were burned to death. The Legion moved their attack to Sendai, where a new flower blossomed quickly in the warmer environment. After battling with the queen Legion, Gamera was almost drained of his energy and forced to use his whole body to prevent the flower's pod from launching. The resulting explosion eliminated everything in Sendai. Desperate, the Legion began to culminate their forces and prepared for an all-out attack on their next target: Tokyo...