How many movies have Eiji Umehara and Takahiro Sakurai collaborated on?

They have worked on 4 movies together! Their first movie together was Donten: Laughing Under the Clouds - Gaiden: Chapter 1 - One Year After the Battle (2017) 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 Peacemaker Kurogane: Friend (2018). They are most known for their animation films together.