How many movies have Akiko Yajima and Tatsuya Oka collaborated on?

They have worked on 4 movies together! Their first movie together was Martian Successor Nadesico: The Motion Picture - Prince of Darkness (1998) while their highest rated movie together was Crayon Shin-chan: My Moving Story! Cactus Large Attack! (2015). They have not worked together since Crayon Shin-chan: Fast Asleep! Dreaming World Big Assault! (2016). They are most known for their animation films together.