Kamen Rider #1 (2016)

45 years ago, a man was subjected to the experiments of the secret organization Shocker and became a cyborg. Since that day, the man's sole mission has been protecting humanity and justice from the threat of Shocker. His name is Takeshi Hongo, the first Kamen Rider. After a long battle overseas, Hongo hears a certain girl is in danger and immediately returns to Japan. He then meets Takeru Tenkuji, Kamen Rider Ghost, who had been investigating the girl's whereabouts.

Unfortunately the movie Kamen Rider #1 is not yet available on HBO Max.