There lived an emperor in China, who had a very beautiful kingdom. Everyone admired his palace and gardens but when they heard the nightingale sing, they declared that it was the best of all. When the emperor heard about the nightingale, he sent his men to bring it for him. When he heard it sing, tears came to his eyes. He kept the bird in his palace in a cage.
One day, the king of Japan sent a beautiful artificial nightingale. This nightingale was covered with precious gems and sang wonderfully too. But it could sing only one song. Everyone forgot the real nightingale, and sadly it flew away. Then, one day, the artificial bird broke its spring and could not sing any longer.
Years passed. The emperor fell ill and was near death. No doctor could cure him. The real nightingale heard this and came to sing for him. Hearing it, the emperor recovered. The bird promised that it would always come and sing for him.