The events pick up two years after the last film. Takeshi Hongo is now a high-school teacher and Hayato Ichimonji is just counting down the days before his cybernetic implants kill him. Our heroes are thrust into action when a bizarre series of murders occur; the calling card being the single "Platinum Smile" playing in the background. A further investigation by our heroes discovers that not only is its singer, Chiharu Kazami, dead, but the single itself is part of Shocker's latest nefarious scheme. The Double Riders soon find themselves battling a band of evil twins, led by two new Shocker Kaijin and Kamen Rider V3, who is none other than Chiharu's brother Shiro Kazami.