The original Kamen Rider manga inspired by Shotaro's previous work, Skullman, which became the basis for the Live Action 1971 Series which has made an impact on Japanese culture and media, similar to the success of Ultraman.

Many manga based on the original Masked Rider series have been published, but only a few were penned and drawn by Ishinomori himself.

The original manga published in 1971 diverged from the plot of the television series in several ways. In the manga, Hongo was outnumbered by twelve Shocker Riders (as opposed to six in the television series) and was subsequently killed. Hayato Ichimonji, one of the twelve Shocker Riders, received a head injury during the fight and regained his conscience as a result. He then turned against Shocker and succeeded Hongo's role as Kamen Rider. However, Hongo was resurrected near the end of the manga story.

(Source: Wikipedia)