Wash whole mung beans and soak in a lot of water with a pinch of salt for 4-6 hours.
After soaking, rinse mung beans. Add them to a pot with 4 1/2 cups of water and a pinch of salt. Bring to a boil and then lower heat to a simmer. Cook until the beans are tender and the skin is split open, about 25 minutes (depending on soaking time and your stove). Skim off any foams during simmering.
While simmering the beans, prepare the aloe vera. Cut off the spiky top and about an inch of the bottom part. Divide the aloe vera leaf into 2 1/2 - 3 inch long sections.
Cut off the spiky edges alongside each section and slice off the green outer skin.
Cut the inner gel into thin strips and place them in a colander. If the inner gel is quite thick, you can slice in half horizontally before cutting into strips. Be careful while cutting since it can be a little slippery.
Sprinkle about 1/4 teaspoon of salt over the aloe vera gel strips. Toss, rinse and wash thoroughly under cold running water. Repeat one or two more times until the aloe vera gel is no longer slimy to completely get rid of the yellow sap (latex).
Once the mung beans are tender, add sugar then add aloe vera gel. Bring back to a simmer and cook for 3-4 more minutes until you see tiny bubbles all over inside the gel. Taste and add more sugar to taste if needed.
Transfer to a clean container to cool. Refrigerate and serve chilled.