Wang Xiaoshuai, actress Yong Mei (left), and actor Wang Jingchun celebrate the win of two Silver Bear awards during the 69th Berlin International Film Festival on Feb 16. [Photo provided to China Daily]

For the 52-year-old director, the film is the epitome of life for millions of Chinese families that have experienced the economic changes over the past 40 years.

"Chinese tradition and philosophy emphasizes the integrity of a family. You will see in the film that the two leading characters adopt a child in their struggle with fate and bid to regain hope. It's a manifestation of the tenacity and kindness of Chinese people," says the director.

Undoubtedly adding to the film's box-office appeal is the appearance of Wang Yuan, who plays the adopted teenager. A member of Chinese boy-band TFBoys, the 18-year-old pop idol who has more than 72 million followers on Sina Weibo, turns in a good performance.

Speaking about his casting, Wang Xiaoshuai says the young actor met his demands for the character, but his many fans who flocked to the film set soon became a distraction. The director says he felt sorry that stardom had made it impossible for Wang Yuan to discuss the script or share performance skills with veteran actors like some other actors of his age.

With a round of test screenings launched from March 15 to 17, the film has so far scored 7.8 points out of 10 on popular review aggregator Douban.

Yet the film's commercial prospects remain uncertain, according to industry observers.

Yu Dong, founder and CEO of Bona Film Group, calls on theater operators to arrange more screenings for the film.

"China only had 1,800 screens and 1,100 cinemas in 2001, but that figure grew to 60,000 screens and 10,000 cinemas last year," says Yu, adding that such a huge market should have the space for artistic films to survive.

So Long, My Son will be released across the Chinese mainland on Friday.