How many movies have Kenzo Koizumi and Otaka Hamana collaborated on?

They have worked on 6 movies together! Their first movie together was Doraemon: Nobita and the Birth of Japan (1989) while their highest rated movie together was Doraemon: Nobita's Three Visionary Swordsmen (1994). They have not worked together since Doraemon: Nobita's Diary on the Creation of the World (1995). They are most known for their animation films together.