Bring a large pot of water to a boil over high heat.
Add the sago and cook on medium heat for 8 minutes, or until the sago is almost fully transparent.
Cover and turn off the heat; let the sago sit for 10 minutes, or until it's fully transparent.
Drain the sago through a fine mesh sieve and rinse with cold water. Set it aside.
Peel the mangoes, cut off the flesh, and remove the pit.
In a blender, combine half the mango, the coconut milk, and the condensed milk. Blend until it forms a smooth mango puree.
Cut the remaining mango into large chunks.
Divide the cooked tapioca pearls and mango mixture between 4 glasses or bowls, and top with chunks of mango (optionally add toppings like coconut jelly).
