How many movies have Chiaki Nanjô and Mototsugu Watanabe collaborated on?

They have worked on 5 movies together! Their first movie together was Young Widow Mourning Convulsion (1990) while their highest rated movie together was Monzetsu OL: Ijô na Zengi (1991). They have not worked together since Groper Train: Let Me Come in the Morning (1992).