How many movies have Kyouhei Yamaguchi and Toshihiko Sahashi collaborated on?

They have worked on 6 movies together! Their first movie together was Kamen Rider Den-O The Movie: I’m Born! (2007) while their highest rated movie together was Kamen Rider Den-O & Kiva: Climax Deka (2008). They have not worked together since Kamen Rider THE WINTER MOVIE: Gotchard & Geats Strongest Chemy★Great Gotcha Operation (2023). They are most known for their science fiction films together.