How many movies have Kiyoshi Hirose and Yasumasa Koyama collaborated on?

They have worked on 4 movies together! Their first movie together was Planetarian: Hoshi no Hito (2016) while their highest rated movie together was Sword Art Online the Movie – Progressive – Aria of a Starless Night (2021). They have not worked together since Sword Art Online the Movie – Progressive – Scherzo of Deep Night (2022). They are most known for their animation films together.