Supporting Riders (サブライダー, Sabu Raidā, Sub Riders)[1][2][3][4] are Kamen Riders that serve as a supportive cast in their respective series. Since Kamen Rider Agito in 2001, it has been a continuous tradition in the Heisei era and currently in the Reiwa era, for every series to feature supporting Riders fighting alongside the Primary Rider. These Riders are the additional Riders of their series, movies and specials. They serve the role as either secondary villains, or as support characters.
Supporting Riders subsets are as follows: