In the Western Jin Dynasty (AD 265~316), the 20-year-old, Lu Ji, brought his younger brother, Lu Yun, and his family to his hometown at small Kunshan Mountain. They studied behind closed doors. The brothers raised a dog that looked similar to a pony that was about 1m high and 1.6m long from head to tail.

The whole body was a black color and was sleek except that its ears, which were golden yellow. That is where it got the name "Huanger", which literally translates into "Yellow Ears". It was fierce and strong and the dog stayed with Lu Ji all the time.

One day, Lu Ji visited a friend a thousand miles away and Huanger also followed him. His friend liked the dog very much. Before parting, he borrowed the dog from Lu Ji and asked him to give the dog to him. Lu Ji was reluctant, but did not know how to refuse his request.

He asked his friend to lock the dog up for at least a half month so that the dog did not track him back to Songjiang. One month later, Huanger was lost. More than 10 relatives, friends and servants of his friends searched the city.

Gradually he forgot Huanger. To his surprise, he received a letter from Lu Ji. In addition to the greeting, Lu Ji particularly mentioned that Huanger had returned home safely except that he had lost much weight.

At 30 years old, Lu Ji became an official in Luoyang. Huanger also followed him. Two months later, Lu Ji missed his home. He wrote a letter and wanted to find somebody to send the letter.

He saw Huanger, so he asked the dog: Huanger, will you bring the letter to our hometown? Huanger nodded and swung his tail. Lu Ji put the letter into a copper tube, sealed the tube with wax and tied the tube to the neck of Huanger.

He patted his head and Huanger left at once. Shortly after, Huanger delivered the letter to his hometown and brought a letter written by Lu Ji's family back to Luoyang. Huanger saved six days on the whole trip compared to a professional messenger. "Huanger delivers letters" immediately became the top news in Luoyang.

This interesting story was written into the Book of Jin. After Huanger died, he was buried in "Huanger's Tomb", which is an attraction of Songjiang.