How many movies have Mariko Takamatsu and Shinichi Watanabe collaborated on?

They have worked on 1 movie together! Their first movie together was Fate/kaleid liner Prisma☆Illya: Prisma☆Phantasm (2019) and was their highest rated movie together. They have not worked together since Fate/kaleid liner Prisma☆Illya: Prisma☆Phantasm (2019).