How many movies have Aki Yamauchi and Etsuko Kozakura collaborated on?

They have worked on 2 movies together! Their first movie together was Yo-kai Watch: The Movie - The Great Adventure of the Flying Whale & the Double World, Meow! (2016) while their highest rated movie together was Yo-kai Watch: Forever Friends (2018). They have not worked together since Yo-kai Watch: Forever Friends (2018).