How many movies have Keiichi Okabe and Yoko Taro collaborated on?

They have worked on 4 movies together! Their first movie together was NieR Music Concert & Talk Live (2016) while their highest rated movie together was NieR Music Concert: The Memories of Puppets (2017). They have not worked together since YoRHa Ver1.3aa (2020). They are most known for their music films together.