How many movies have Shinji Oosawa and Wataru Ishii collaborated on?

They have worked on 1 movie together! Their first movie together was Ôoku: Tsubomi no ran—Ashita e no chigiri (2006) and was their highest rated movie together. They have not worked together since Ôoku: Tsubomi no ran—Ashita e no chigiri (2006).