How many movies have Kazuhiko Seki and Nana Mizuki collaborated on?

They have worked on 4 movies together! Their first movie together was Magical Girl Lyrical Nanoha: The Movie 1st (2010) and was their highest rated movie together. They have not worked together since Magical Girl Lyrical Nanoha: Detonation (2018). They are most known for their animation films together.