The Chinese emperor has many concubines but only truly loves his first wife. When a jealous concubine learns that a child will be born to the emperor, she tries to remove her rival with a magic potion. Instead of dying for the poison, the first wife is turned into a nightengale and continues to charm the emperor with her song.
In spite of her schemes, the concubine can never win the king's heart, and he sinks into such a deep depression that he neglects to rule his kingdom. The land can only be saved by the return of the bird of the night.
This fairy tale film is loosely based on Hans Christian Andersen's "The Nightengale." The charming Asian-style animated characters were created using cut-out animation figures with attached hands and faces made of porcelain.