How many movies have Do Hien and Le Mai collaborated on?

They have worked on 4 movies together! Their first movie together was Case Closed: The Crimson Love Letter (2017) while their highest rated movie together was Maquia: When the Promised Flower Blooms (2018). They have not worked together since Case Closed: The Fist of Blue Sapphire (2019). They are most known for their animation films together.