How many movies have Nobuhiro Otsuka and Yukihiro Shibutani collaborated on?

They have worked on 3 movies together! Their first movie together was Naruto Shippuden the Movie: The Will of Fire (2009) and was their highest rated movie together. They have not worked together since Natsume's Book of Friends: Ephemeral Bond (2018). They are most known for their animation films together.