Place sago in a saucepan and cover with water; bring to a boil. Reduce heat and simmer for 5 minutes. Remove from heat, cover saucepan, and let sit until sago becomes translucent, about 5 minutes. Drain.
Stir sugar into 1/3 cup plus 2 tablespoons hot water in a bowl until dissolved.
Place sugar mixture into a blender; add 3/4 of the mango and blend until smooth. Chill in the refrigerator for 20 minutes.
Stir sago and 1/2 of the pomelo into blended mango mixture and mix well. Spoon into 6 shot glasses and top with coconut cream and remaining mango and pomelo.