How many movies have Jiro Okamoto and Seiji Takaiwa collaborated on?

They have worked on 12 movies together! Their first movie together was Kamen Rider ZO (1993) while their highest rated movie together was Kamen Rider Den-O & Kiva: Climax Deka (2008). They have not worked together since Heisei Rider vs. Showa Rider: Kamen Rider Wars feat. Super Sentai (2014). They are most known for their science fiction films together.