There are two kinds of adzuki beans, one is called Peacock adzuki bean, which has light yellow flowers and strong fragrance. In autumn, a string of curved and flat pods will be produced, and each pod contains 10- 12 red bean seeds as hard as ivory. The other is called two-color sea bean, which grows on Ceylon Island. Red bean seeds are mixed with black spots.

In ancient India, sea red beans were also called "magic beans". The harvester knocked on the shell of the pod and split it in half, then carefully searched for the bean seeds carved by the jeweler into elephant patterns. Once they find these "magic beans", make a wish for them, at most 12 wishes (one wish for each magic bean). It is said that the result is very effective. Although this is only a myth, sea red beans do have high practical value. Because of its hard wood, it is suitable for making high-grade furniture and various ornaments. Bean seeds of sea beans can also be used to make necklaces, bracelets and earrings, and their appearance is no less than that of jewelry made of natural gems.

Another feature of sea beans is that the weight of each bean seed is exactly the same, which is 0.26 g, so in ancient times, jewelers in Southeast Asia used it as a natural weight to weigh gold or other precious metals. In Malaysia and Indonesia, sea beans also have special agricultural value, and their dense branches can provide shelter for coffee trees and Dianthus, making these plants grow exceptionally well.