How many movies have Kazuhiko Seki and Yoko Hikasa collaborated on?

They have worked on 4 movies together! Their first movie together was Trinity Seven: Eternity Library & Alchemic Girl (2017) while their highest rated movie together was Trinity Seven: Heaven's Library & Crimson Lord (2019). They have not worked together since Trinity Seven: Heaven's Library & Crimson Lord (2019). They are most known for their action films together.