How many movies have Hiroshi Butsuda and Keiko Sakai collaborated on?

They have worked on 3 movies together! Their first movie together was Kamen Rider × Kamen Rider W & Decade: Movie War 2010 (2009) and was their highest rated movie together. They have not worked together since Kamen Rider × Super Sentai × Space Sheriff: Super Hero Wars Otsu: Heroo! Answers (2013). They are most known for their science fiction films together.