Kamen Rider Super-1 is a movie based off the Kamen Rider Series entry of the same name. It sees Super-1 teaming up with the previous eight Kamen Riders, who make their return after seemingly sacrificing themselves to destroy the Great Boss of Neo-Shocker in the finale of Kamen Rider Skyrider.
Kamen Rider Super-1: The Movie
The Dogma Kingdom attacks the Matagi (mountain tribe) village of Yamabiko to steal the sacred Flying Dragon Fortress and wreak havoc all over Japan. Six children from the fallen village take refuge in a nearby town, keeping their identities as Matagi citizens a secret. Kamen Rider Super-1 must protect these children from the Dogma Kingdom, as they hold the secret to the Flying Dragon Fortress’ weakness.
Kamen Rider Super-1: The Movie
This movie was released between episodes 21 and 22. However, at the end of episode 21, General Megarl says that he would stake everything he had to defeat Super-1 the next time, pretty much describing episode 22.
Kamen Rider Super-1: The Movie
And General Megarl was chided for failing the strategy to steal the Five Hands (episode 21) at the beginning of episode 22, which means episode 22 came right after 21. Therefore, the closest and best fit for the movie would be right after episode 20. It also explains well Terror Macro being really mad at General Megarl at the beginning of episode 21.
Kamen Rider Super-1: The Movie