Taki Kazuya, an Interpol agent residing in New York City, is currently investigating a series of disappearances and murders that appear to be caused by something inhuman. He frequently recounts stories about his friend, a cyborg hero known as Kamen Rider, who years earlier in Japan dismantled the evil organization Shocker, saving people from monsters without seeking any reward for his actions. However, the only individuals who believe his tales are a group of orphans he has befriended. When one of the orphans is transformed into a monster, Taki tracks down the creature responsible and attempts to fight it in his own costume, adopting the name of a new Kamen Rider. He fares poorly against the creature and is on the verge of being killed. At that moment, none other than Takeshi Hongo, the original Kamen Rider, comes to his rescue. Hongo and a newly inspired Taki team up and manage to defeat the creatures. Afterward, Hongo informs Taki that a new danger is rising to threaten humanity and asks for his help before setting off to find more allies, the eight other Kamen Riders with whom he was once a team. Taki continues his work with Interpol, along with assisting Hongo's search.