How many movies have Hiromi Sakahigashi and Kazuko Itooka collaborated on?

They have worked on 3 movies together! Their first movie together was K-On! The Movie (2011) while their highest rated movie together was Tales of Zestiria: The Shepherd's Advent (2014). They have not worked together since Aria the Avvenire (2015). They are most known for their animation films together.