Keisuke Jin tries to save his father Dr. Jin from an attack by G.O.D. and is shot and killed in the process. However, in exchange for his own life, Dr. Jin resurrects Keisuke as the cyborg Kaizorg! Learning of his mission from Dr. Jin's last words, Keisuke becomes Kamen Rider X and battles G.O.D.!

1-nen no Gakushu - Junichi Ikeda (August 1988-March 1991) 2-nen no Gakushu - Masatoshi Nakajima (August 1988-March 1991), Keizaburo Kuwahara (April 1991-March 1992) 3-nen no Gakushu - Morihiko Ishikawa (August 1988-March 1991), Masatoshi Nakajima (April 1991-March 1992) 4-nen no Gakushu - Yoshiaki Tsuhara (August 1988-March 1991), Morihiko Ishikawa (April 1991-March 1992) 5-nen no Gakushu -Shotaro Ishinomori (April 1989-March 1991), Yoshiaki Tsuhara (April 1991-March 1992) 6-nen no Gakushu - Gosaku Ota (August 1988-March 1991), Shotaro Ishinomori (April 1991-March 1992)