How many movies have Atsushi Kaji and Toshihiko Seki collaborated on?

They have worked on 8 movies together! Their first movie together was Castle in the Sky (1986) while their highest rated movie together was Kamen Rider Den-O & Kiva: Climax Deka (2008). They have not worked together since Kamen Rider Decade: All Riders vs. Dai-Shocker (2009). They are most known for their action films together.