are an idol group developed by Avex Trax and Ishimori Productions to commemorate the Kamen Rider Series' 40th anniversary in 2011. Each of the group's current members represent one of the protagonists of the Kamen Rider Series. The group made their premiere at an event featuring members of Columbia Music Entertainment's Project.R group, the musical collaboration who provides music for the Super Sentai series. The group's debut songs were and . The group's debut songs were played on the DJ HURRY KENN Ride the Groove Internet radio program, the successor to the Wind Wave radio programs from the Kamen Rider W series. The group's debut single is "Let's Go RiderKick 2011", serving as the theme song for ' with "Koi no Rider Kick" and "Heart no Henshin Belt" as the single's B-sides. A second single titled "KAMEN RIDER V3" was released on August 3, 2011, with the PV having a cameo by Hiroshi Tanahashi.