The Chinese, who have been innovators in so many areas, are now revealed to have formalized the BFF relationship as long ago as 1839. In Hunan, when two women were Best Friends Forever, they were laotong. This was a relationship that could begin with the agreement of their parents before birth, and persist independent of marriage, children or the changing fortunes of life. It is at the heart of Lisa See's period best-seller Snow Flower and the Secret Fan, and has inspired a film that carries the concept into the present day.