How many movies have Masaru Yokoyama and Norihiro Koizumi collaborated on?

They have worked on 3 movies together! Their first movie together was Chihayafuru: Part I (2016) while their highest rated movie together was Chihayafuru: Part III (2018). They have not worked together since Chihayafuru: Part III (2018). They are most known for their romance films together.