How many movies have Akira Toriyama and Mitsuko Horie collaborated on?

They have worked on 2 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: Mystical Adventure (1988). They have not worked together since Dragon Ball: Mystical Adventure (1988).