A young cowherd named Niulang, came across seven fairy sisters bathing in a lake. Encouraged by his mischievous companion the ox, he steals their clothes and waits to see what will happen. The fairy sisters elect the youngest and most beautiful sister Zhinü (the weaver girl", who represents the star Vega)to retrieve their clothing.

She agrees to do so, but since Niulang has seen her naked, she must agree to his request for marriage. She proves to be a wonderful wife, and Niulang to be a good husband. They lived happily and had two children. But the Goddess of Heaven finds out that Zhinü, a fairy girl, has married a mere mortal human. She is furious and orders her to return to Heaven.

Down on Earth, Niulang is very upset that his wife is gone. Suddenly, his cow begins to talk, telling him that if he kills him and puts on his hide, he will be able to go up to Heaven to find his wife. Crying bitterly, he killed the cow, put on the skin. Carrying his two children with him, he went off to Heaven to find Zhinü. The Goddess found out that he had come and was very angry. Taking out her hairpin, the Goddess scratched a wide river in the sky to separate the two lovers forever (thus forming the Milky Way, which separates Altair and Vega).

Zhinü must sit forever on one side of the river, sadly weaving on her loom, while Niulang watches her from afar and takes care of their two children But once a year all the magpies in the world would take pity on them and fly up into heaven to form a
bridge.