How many movies have Hiroyoshi Koiwai and Tomomi Maruyama collaborated on?

They have worked on 3 movies together! Their first movie together was Rurouni Kenshin Part II: Kyoto Inferno (2014) while their highest rated movie together was Rurouni Kenshin Part III: The Legend Ends (2014). They have not worked together since Museum (2016). They are most known for their fantasy films together.