How many movies have Akinori Nagaoka and Rei Sakuma collaborated on?

They have worked on 6 movies together! Their first movie together was Go! Anpanman: The Shining Star's Tear (1989) while their highest rated movie together was Go! Anpanman: Baikinman's Counterattack (1990). They have not worked together since Soreike! Anpanman: Donburimantorio no Otsukai (2011). They are most known for their animation films together.