How many movies have Kiyoshi Hirose and Yoshihiro Sono collaborated on?

They have worked on 3 movies together! Their first movie together was Cocolors (2017) while their highest rated movie together was Cells at Work!: A Gut-wrenching Resurrection of the Formidable Enemy! (2020). They have not worked together since Cells at Work!: A Gut-wrenching Resurrection of the Formidable Enemy! (2020). They are most known for their animation films together.