Boil 1 cup water with 2 tbsp sugar. Add tapioca and cook for 35 minutes. Drain. Set aside.
Boil agar agar in 1-1/2 cups water with pineapple syrup for 5 minutes. Strain over bowl. Add tapioca, mango and sugar. Stir. Arrange each slice of Pineapple into desired individual mold. Pour 1/4 cup tapioca mixture. Cover and chill until set.