Hiroshi Tsukuba is the main protagonist of the 1979 Kamen Rider series. He is a young man who chances upon the activities of Neo Shocker, and is forcibly converted by the evil organization into a cyborg known as the Kamen Rider. After teaming up with his predecessors, he is bestowed the title of Skyrider.
Hiroshi is a young man who hang glides for fun and studied karate under Ryoichi Miyoshi. Three years prior, he lost his parents and sister in a car crash. While on a picnic with his friends, Hiroshi witnessed Professor Keitarō Shido being pursued while hang gliding and saves him from a gang of Ari Commandos. Soon after, Hiroshi finds his friends have been all murdered for his meddling before being approached by Midori Kanō, who takes him to Shido, as the man informs Hiroshi of the terrorist organization Neo Shocker.