How many movies have Gaku Oshida and Shin-ichiro Shirakura collaborated on?

They have worked on 4 movies together! Their first movie together was Kamen Rider Zi-O (2018) while their highest rated movie together was Kamen Rider Zi-O the Movie: Over Quartzer (2019). They have not worked together since Kamen Rider Zi-O NEXT TIME: Geiz, Majesty (2020). They are most known for their science fiction films together.