All Together! Seven Kamen Riders!!

The special opens with Tobei Tachibana taking some kids to a Kamen Rider Show. Just as he is reminiscing about all the heroic modified humans he is lived alongside (Rider 1, Rider 2, V3, Riderman, X, Amazon, Stronger, and Tackle), the first seven Riders gradually show up to greet him in their human guises, unrecognized by the crowds. When it is revealed that the kaijin onstage are real, not actors, the Riders transform to save the crowd and Rider actors, uniting their power to defeat the Delza Armys true leader, Great General Darkness in his hideout beneath the stadium.

—kzakiy