How many movies have Jirō Ishikawa and Takeshi Niizato collaborated on?

They have worked on 9 movies together! Their first movie together was New Hotaru The Hyper Swindler (2005) while their highest rated movie together was New Hotaru The Hyper Swindler 4 (2006). They have not worked together since Akiho Yoshizawa Special: An Attraction to Girl Paradise (2008). They are most known for their drama films together.