"I am justice" Seven years after the meteorite fall disaster in Shibuya. The threat of the extraterrestrial life form "worm" that mimics humans approaches humankind. The secret organization ZECT has developed a "Masked Rider System" that enables clock-up = ultra-high-speed combat to counter worms. However, the system chooses the fateful man, Souji Tendou, as the Kamen Rider, regardless of the organization's speculation. In this way, Tendou began to fight as Kamen Rider Kabuto at his own discretion.