How many movies have Iwamitsu Itô and Naoko Watanabe collaborated on?

They have worked on 2 movies together! Their first movie together was Memoru in the Pointed Hat: Marielle's Jewelbox (1985) while their highest rated movie together was Dragon Ball: Sleeping Princess in Devil's Castle (1987). They have not worked together since Dragon Ball: Sleeping Princess in Devil's Castle (1987).