The convention of giving “li xi” has its roots in the folklore about the ogre called Tuy. Once upon a time, living in a huge peach blossom tree in the East Sea were all evil spirits on Earth. While being kept inside the tree and controlled by deities, they always tried to escape and harmed people. However, on New Year's Eve , as the deities had to gather together at the Heavens, Tuy would appear, rubbing small children’ head to make them burst into loud wails and get high fever. Thus, the whole family had to stay awake all night to protect the children from the ogre.

However, some Deities while once stopping by a village had turned themselves into gold coins. Parents covered those coins in red cloth and placed under a child’s pillow. Later, when Tuy came, the coins sparkled and drove it away. Good news quickly spread out all over the country, and from that time on, Vietnamese have had the tradition of giving small children lucky money in red envelope on the first day of Lunar New Year.