Enormous thorny tendrils break through streets of Tokyo's business district, while others break through subbasements to feed off of those caught in their grasp. The plant pushes up into the offices of the Mainichi Shimpo News and eventually through the roof, where its poisonous flower blooms. Professor Ichinotani hypothesizes this primordial plant, Juran, has revived due to manmade changes to the environment, but argues with Professor Genda; Ichinotani wants to destroy the Monster, while his colleague wants to study it.
原因不明の地震が頻発し、地中から現れた巨大な植物の根が人々を襲う事件が起きた。そして、ビルを突き破ってマンモスフラワーが開花し、毒花粉を撒き散らし始める…。
