Wash and rinse blueberries. Pat dry and set aside. Prepare jelly moulds. Arrange equal portions of blueberries in the moulds. Set aside in the refrigerator. Mix sugar and konnyaku powder in a small bowl. Pour hot water and Ribena into a saucepan and place over stove. Slowly add konnyaku sugar mixture and stir to dissolve.
Allow contents to boil for 5 minutes. Remove from heat and stir until the bubbles disappear.
Fill chilled moulds with konnyaku mixture. Let them cool down to room temperature before storing them in the refrigerator. Serve chilled.