How many movies have Nanako Ninomiya and Takahiro Sakurai collaborated on?

They have worked on 4 movies together! Their first movie together was Peacemaker Kurogane: Belief (2018) while their highest rated movie together was Donten: Laughing Under the Clouds - Gaiden: Chapter 2 - The Tragedy of Fuuma Ninja Tribe (2018). They have not worked together since Fate/Grand Order the Movie: Divine Realm of the Round Table: Camelot Wandering; Agateram (2020). They are most known for their action films together.