How many movies have Akiko Matsuo and Megumi Oohara collaborated on?

They have worked on 2 movies together! Their first movie together was Doraemon: Nobita's Great Battle of the Mermaid King (2010) while their highest rated movie together was Doraemon: Nobita and the New Steel Troops: Winged Angels (2011). They have not worked together since Doraemon: Nobita and the New Steel Troops: Winged Angels (2011).