Cook the sago pearls: Bring water to a boil, then add sago pearls. Cook for 10-15 minutes, stirring occasionally, until translucent. Drain and rinse with cold water.

Prepare the mango: Blend the diced mango with a little water to make a smooth puree. Set aside.

Make the syrup: In a pot, heat coconut milk, sugar, and water until the sugar dissolves. Let it cool.

Combine: In a bowl, mix the cooked sago, mango puree, and coconut syrup. Stir well.

Serve: Chill in the fridge for an hour. Serve cold, with ice cubes if desired.