"I didn't conceive the story. I heard about it from people involved in the project," says Ou, speaking on the sidelines of a promotional event for the film in Beijing.
Ou worked on the project over the course of six years. During one visit to interview local people, she was introduced to an elderly singer known as one of the "five golden flowers" - a reference to the then most-celebrated female singers of the Dong ethnic group who performed for state leaders in the 1950s.
The elderly lady recalled her early years, involving an unforgettable love affair with a man who stayed single after the couple were forced apart.
"Her story touched me. It's impossible to imagine that someone nowadays will wait for an entire lifetime for a love that may never be returned," says the 34-year-old filmmaker.
As a native growing up in the Qiandongnan Miao and Dong autonomous prefecture, Guizhou province, Ou was fascinated by local legends from a young age and in 2002 began to visit the remote villages scattered around the mountains there.
After she graduated from the Beijing Film Academy, Ou began to make movies about the Dong and Miao people, making her the first film director to come from either of the ethnic groups.
