Professor Daidōji 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 Daidōji's daughter, who is celebrating her birthday. Now the Kamen Riders, along with FBI agent Kazuya Taki, must protect Daidōji's daughter and prevent Shocker from obtaining the plans.
佐々木剛
as Hayato Ichimonji / Kamen Rider #2
藤岡弘、
as Takeshi Hongo / Kamen Rider #1
小林昭二
as Tobei Tachibana
矢吹二朗
as Kazuya Taki
天本英世
as Dr. Shinigami
沖わか子
as Yuri
鳩山エミリ
as Emi
Yoko Sugibayashi
as Mika
三浦康晴
as Goro
伊豆肇
as Dr. Daidōji
Hiroyuki Miya
as Assistant Ano
斉藤浩子
as Tamami Daidōji
