Place 12 2-inch silicone cups on a tray. Put 2 raspberries and 5 blueberries in each cup. Set aside.
Bring water to a boil in a medium sized saucepan. Add sugar and agar-agar, stirring constantly until sugar and agar-agar dissolve, about 5 minutes. Stir in rose essence. Turn off heat. Fill moulds about ¾ full with agar-agar mixture.
Allow agar-agar to set in the refrigerator, at least 30 minutes. Unmold and serve cold.