How many movies have Hiroyoshi Koiwai and Kazuhiro Sawataishi collaborated on?

They have worked on 6 movies together! Their first movie together was Rurouni Kenshin Part I: Origins (2012) while their highest rated movie together was Rurouni Kenshin Part III: The Legend Ends (2014). They have not worked together since Rurouni Kenshin: The Final (2021). They are most known for their action films together.