Kamen Rider Spirit : The Legend > Riderman

Riderman

Story -- Yuki Joji had a promosing future as Deathtron's elite scientists. However, General Armor, jealous of Yuki's abilities and afraid he would be replaced, had claimed Yuki a traitor and sentenced him to death by acid pool. Yuki's fellow scientists were able to save him from certain death, but he had already lost his right arm to the acid. After attaching a new cybernetic arm, Yuki's assistants were attacked and killed by a Kaijin who was chasing after Yuki. Burning with rage, Yuki donned a helmet, reinforced clothes, and adopting the name Riderman, swore revenge on General Armor. Originally Riderman viewed V3 as the enemy, but when he learned that Deathtron was really an evil organization, instead of one dedicated to helping humanity, as Yuki was lead to believe, he decided to team up with V3 to help combat Deathtron. When Deathtron launches a Pluton Rocket at Tokyo, Riderman sacrifices himself to stop the rocket. As the rocket explodes, V3 yells out "You are Rider #4!' Riderman was unable to exact his revenge, but V3 took up where his friend left off, defeating General Armor and Deathtron.
Name
Yuki Joji

Actor Name
Yamaguchi Akira
Years on TV
12-8-1973 ~ 2-2-1974
Insect Motif
Mantis

Buddies
Kazami Shiro
Villian
Deathtron
Belt
Riderman's belt

Cycle
Riderman Machine = 200km/h ; 400 horsepower

--Special Techniques--
Rope Arm

Riderman's Default Arm, which is used in various ways. As means of escape, climbing, and combat. The arm itself has modified attachments for Yuuki to use and adjust to various situations. There is his default Hook Arm, with hook attachment, for climbing and combat. When the mace end is attached, he gets his Swing Arm, which can be extended and used as a flailing weapon. Then, there's the Net Arm, where Yuuki's arm can shoot out a net to capture and restrain enemies (by Kamen Rider Spirits, it appears that this net is fireproof). Finally, there's the Sickle Arm which has been seen in various promotion; and yet, wasn't used in the series. Based on the photos, it is assumed it is simply used for combat.
Power Arm

Riderman's strongest weapon, which increases Yuuki's attack in battle. Its primary use is to hack away at both obstacles, such as doors, and opponents. This weapon could've been easily used as a finishing attack according to some fans.
Drill Arm

Another weapon could've been easily used as a finishing move. It was only seen being used as an infiltration tool. It must be plugged in order for it to work best, although it will still work otherwise (by Kamen Rider Spirits, it appears to work just fine without external power).
Machine Gun Arm

This weapon was only seen in the Kamen Rider Spirits manga. It was used to destroy the crab mutant in the manga, which had the appearance to be a regular machine gun.