Rinse the sushi rice under cold water until the water runs clear to remove excess starch.
Combine the rinsed sushi rice, coconut milk, water, and salt in a medium saucepan and stir gently.
Bring the mixture to a gentle boil, reduce heat to low, cover, and simmer for about 20 minutes until liquid is absorbed and rice is tender.
Remove from heat and let sit covered for an additional 10 minutes before fluffing with a fork.
Dice the mango into small cubes and set aside for topping the warm sticky rice.
Scoop portions of the warm sticky rice onto plates and top generously with fresh mango pieces before serving.