Kagaku Ninjatai Gatchaman? ^_^
Close, but not it.
Hey, it Kamen Rider, right? I don't know the title of the movies he was in though...
You are right, it is Kamen Rider. More specifically it is Kamen Rider Kabuto: God Speed Love. It's not the best in the series, it's pretty average compared to the better movies but it's entertaining to those who like the tokusatsu genre. Since you knew the name of the series the movie belongs to, I'd say it's your turn.