A poster for the film Twenty Two. [Photo/mtime.com]

Guo also said he did not expect much from the film before its screening.

"As a tiny film during the summer release season, we only expect the film would have a small survival space, and the targeted box office was 6 million yuan," he said.

"It means that there would be 200,000 people watching the film in the cinemas.

"From 1932 to 1945, at least 20,000 Chinese women were forced to be 'comfort women' by the Japanese army."

Guo said he believed the meaning of Twenty Two was more important than the box office, and added he would have been satisfied with only 1 percent screenings in theaters.

"I am not going to earn one penny from the film," he said. "Except for the cost, the rest of the revenue will all be donated to these women."

The 90-minute documentary featured 22 "comfort women" in China, who peacefully shared their take and experience in history. As of July, only nine of the 22 women in the movie are still alive.

Guo had shot a short film Thirty Two in 2012, recording comfort woman Wei Shaolan in the Guangxi Zhuang autonomous region, which can be watched online.

To watch the short film Thirty Two, click here.