How many movies have Akio Otsuka and Hajime Katoki collaborated on?

They have worked on 6 movies together! Their first movie together was Mobile Suit Gundam: The Origin I - Blue-Eyed Casval (2015) while their highest rated movie together was Mobile Suit Gundam: The Origin III - Dawn of Rebellion (2016). They have not worked together since Mobile Suit Gundam: The Origin VI – Rise of the Red Comet (2018). They are most known for their animation films together.