Rinse the sago pearls under cold water to remove excess starch.
Bring 1 cup of water to a boil in a pot.
Add the sago pearls to the boiling water and stir gently.
Reduce heat to low and simmer for about 15 minutes, stirring occasionally.
Once the sago becomes translucent, remove from heat and let it sit for 10 minutes.
Drain the sago and rinse under cold water to stop cooking.
In a separate pot, combine coconut milk and sugar; heat until sugar dissolves.
Mix the cooked sago into the coconut milk mixture.
Allow the mixture to cool to room temperature.
Serve in bowls topped with diced mango and garnish with mint leaves.