Lu said the idea of the movie came after he completed "Kekexili" in 2004. Lu's second movie, which was about people risking their lives to save endangered Tibetan antelopes from poachers, won wide acclaim from critics and proved to be a box office hit in China.

Director Lu Chuan

"Chinese people were frequently portrayed as weak and helpless victims in the massacre. It's not totally true. There was resistance. That part of history was more or less left out," he said.

"Some people might suspect that by emphasizing resistance, I am making an excuse for the massacre. This is wrong. Resistance (of the defeated) doesn't legitimize massacre (by the victor)," he said.

After more than three years of extensive research, however, Lu underwent "a tremendous shift in perspective." The final version is radically different in storyline and point of view.

"At first, I concentrated on representing the 'Rape of Nanking' (by Iris Chang), but gradually, I wanted to explore the laws of nature governing war and how they give rise to massacres," he said.

In the monochrome movie, Lu tried to see the massacre from the eyes of different people, including an ordinary Japanese soldier Kakokawa, who joined the Imperial Japanese Army out of loyalty to the Japanese emperor, experienced shock and pain in the war and ended up committing suicide in Nanjing.

This narrative approach elicited divided reactions after it was screened for movie critics, media and survivors of the massacre. Many said the storyline of the Japanese soldier was convincing and provided an in-depth look into the war.

"I remember coming out from the screening with tears in my eyes. It was powerful," said Bey Logan, vice president of Asian Acquisitions and Co-production, the Weinstein Company, an independent American film studio.

"The film presents history in very human terms, which is why it's so moving. I think a one-note film about heroic Chinese soldiers and evil Japanese soldiers might be epic, but it wouldn't be nearly as an engaging, emotionally, as this one is," he said.