How many movies have Ryuuou Yamaguchi and Yoshio Kitazawa collaborated on?

They have worked on 3 movies together! Their first movie together was Kyotaro Nishimura's Mystery: Railway Inspector 16 (2016) and was their highest rated movie together. They have not worked together since Kyotaro Nishimura Travel Mystery 68: Disappearing Woman in Yamagata (2017). They are most known for their mystery films together.