How many movies have Daiki Wakabayashi and Sen Arima collaborated on?

They have worked on 4 movies together! Their first movie together was Transformation Doll (2015) while their highest rated movie together was Onna sagi-shi to bijin singer: O-atsui no wa dotchi? (2015). They have not worked together since Big Breasts VS Big Cock ~ Perverted Tower Love (2016).