Toei's CEO Shinchiro Shirakura had leaked a major Kamen Rider Reiwa the First Generation surprise by mistake on his Twitter.
He was doing QNA with Kamen Rider Fans on twitter. One of the Korean Fans had asked about his favorite Kamen Rider Episode and Another Rider. Well for this Shinichiro Shirakura had replied saying that his favorite episode would be Reiwa the First Generation and favorite Another Rider is Another Zero-One and Another Ichigou.
Another Ichigou is the Another Rider of Kamen Rider 1. But it is not sure why they are going to bring the Another Rider of Kamen Rider 1 who is actually from Showa Era. How is Showa Era Rider related to a Reiwa featuring Heisei Rider movie?
Some fans speculate that this Rocking Hopper Rider is the Another Ichigou.
In the end, he has also revealed that Kamen Rider Tsukuyomi's Finisher could possibly appear in the movie.