Hongo Takeshi awakens to discover he has been transformed into a grasshopper-hybrid cyborg. Becoming the Masked Rider, he must fight the mysterious evil organization SHOCKER to protect all of mankind.

College student and motorcycle enthusiast Takeshi Hongo is abducted by the evil organization Shocker and converted into a cyborg as part of their plans for world domination. Before they can brainwash him to do their bidding, he escapes and uses his new enhanced abilities as Kamen Rider to wage a one-man war against Shocker.