在这部假面骑士对修卡动作/冒险/剧情片中,研究出人工重力装置CX程式的大道寺博士被死神博士追杀。原来，死神博士一心利用CX程式改变地球地轴，将日本列岛沉入海底。这次，本乡和一文字两位假面骑士再次联手对抗邪恶的地狱组织……
Professor Daidoji has developed a gravity machine called the GX Device. Unfortunately, Shocker wants it; so they attack the professor and destroy his laboratory, but come home empty-handed. Shocker's agents find out that the plans for the GX Device are with Daidoji's daughter, who is celebrating her birthday. Now the Kamen Riders, along with FBI agent Kazuya Taki, must protect Daidoji's daughter and prevent Shocker from obtaining the plans.
