Chang was brought from China by her brother, Lin Chang then he tried to sell her as a wife to a rich man through the help of a matchmaker. When the man, Sun Zhang, rejected her because of her appearance she offered to work in the family shop with her brother selling traditional Chinese medicine, that dealt illegal animal parts on the side.
Delivery men, Deng Shi and Ling Fu, came in were waiting for a way to smuggle through bear bile, but it would take a few months as the whole illegal trade was under scrutiny. Lin suggested they use Mei Chang to recover the shipment, as, as a woman and an unattractive woman at that, she would be invisible.
On one delivery occasion, she noticed that the dealer was trying to rip them off by giving them ping pong balls instead of eggs, thus starting a fight between the dealer. She knocks the dealer unconscious just as he is about to shoot Fu and Fu declares that he owes her.
Mei Chang later exacts revenge on Mr. Sun, who rejected her for marriage by telling Fu and his men to cut out his gallbladder