How many movies have Mami Koyama and Tomekichi Takeuchi collaborated on?

They have worked on 3 movies together! Their first movie together was Dr. Slump and Arale-chan: Hoyoyo! The Treasure of Nanaba Castle (1984) while their highest rated movie together was Dragon Ball: Curse of the Blood Rubies (1986). They have not worked together since Dragon Ball: Sleeping Princess in Devil's Castle (1987). They are most known for their animation films together.