How many movies have Hikaru Yamamoto and Kengo Motoi collaborated on?

They have worked on 4 movies together! Their first movie together was Kamen Rider × Kamen Rider W & Decade: Movie War 2010 (2009) while their highest rated movie together was Kamen Rider W Forever: A to Z/The Gaia Memories of Fate (2010). They have not worked together since Kamen Rider × Kamen Rider OOO & W Featuring Skull: Movie Wars Core (2010). They are most known for their science fiction films together.