How many movies have Bokuzo Masana and Keiichirō Yoshida collaborated on?

They have worked on 4 movies together! Their first movie together was Taxi Driver's Mystery Diary 36 (2014) while their highest rated movie together was Taxi Driver's Mystery Diary 37 - Mystery of Double Homicides from Tokyo to Hamamatsu (2015). They have not worked together since Inspector Souichi Habu 4 ~The Man Called Poisonous Habu~ (2016).