1. Wash the black rice, soak it in water for 4 hours or more, put the soaked black rice into the rice cooker, and add the water;
2. Press the cooking key, and stir with the spoon after the cooking switch jumps up;
3. Take a semicircle container, flush it with water to prevent sticking, put it into black rice and compact it, and put it into a bowl;
4. Wash the mango, cut it in half, remove the core and skin, and cut into small pieces;
5. Pour the coconut juice into the small pot, and put in the sugar according to the preference;
6. Heat until sugar melts, do not boil, pour into a small bowl, and put the mango dice and black rice balls on the side.