How many movies have Tetsuya Watanabe and Yoshihiro Watanabe collaborated on?

They have worked on 2 movies together! Their first movie together was Heaven's Lost Property the Movie: The Angeloid of Clockwork (2011) while their highest rated movie together was The Testament of Sister New Devil: Departures (2018). They have not worked together since The Testament of Sister New Devil: Departures (2018).