Bring water to a boil. Add in sago and simmer for 15 minutes.
Add in sugar, juice, evaporated milk and gata (coconut milk).
Simmer for another 10 minutes, stirring once in a while to prevent sago and milk from burning.
Cook until liquid has almost evaporated.
While still hot, blend in mangoes and scoop about 1/2 cup of the mixture into molds or serving containers and let cool. Chill before serving.