How many movies have Akio Otsuka and Koji Masunari collaborated on?

They have worked on 2 movies together! Their first movie together was Nadia: The Secret of Blue Water - Nautilus Story I (1991) while their highest rated movie together was Naruto the Movie: Guardians of the Crescent Moon Kingdom (2006). They have not worked together since Naruto the Movie: Guardians of the Crescent Moon Kingdom (2006).