Before penning the movie Great Cold, scriptwriter Lyu Pinpin collected all the books and documents she could find about the plight of "comfort women"-the female victims from China, South Korea and the Philippines who were forced into sexual slavery by invading Japanese soldiers before and during World War II.

While researching the brutality of Japanese soldiers against Chinese women during the War of Resistance Against Japanese Aggression (1931-45), Lyu says she was so sickened and distressed by what she read that she found it difficult to fall asleep night after night. And as the mother of a 6-year-old boy, the writer was consumed with anger when she read about the rape of Chinese women and the killing of their infants by Japanese troops.

"It is one of the darkest chapters in history, and should never be forgotten. Those surviving elderly women deserve a feature film that shows more people about the horrors they suffered and their courage in speaking out," the 41-year-old writer tells China Daily during a preview of the movie at Peking University on Jan 10.

And her hopes were realized with the general release of Great Cold across China on Jan 12. The film examines the plight of the former comfort women, the misery inflicted on the victims and Japan's refusal to face up to its wartime past. It has won praise from viewers and scholars alike.

Related: Documentary on 'comfort women' faces history, wins box office