Put the coconut milk, red bean puree and kona kanten in a blender, and blitz until completely smooth. Pour this mixture through a double mesh seive into a small saucepan, discarding any remaining solids.
Heat the saucepan over medium low heat, stirring constantly until it starts steaming (but not until it boils). Pour the mixture into individual ramekins and allow them to come to room temperature before putting in the refrigerator to set.
To make the blueberry sauce, just add the thawed blueberries to the blender and blend until smooth. Taste, then add agave nectar as needed to sweeten.
To serve, just unmold the ramekins and pour the blueberry sauce on top.