An advertisement centred around "leftover women" in China has gone viral, provoking an emotional debate about single women in the country.

The issue of unmarried females, often stigmatised as "sheng nu" or leftover women, has long been a topic of concern in a society that prioritises marriage and motherhood for women.

Called the "Marriage Market Takeover", the four-minute long documentary-style video was commissioned by Japanese beauty giant SK-II.

In a statement to the BBC, SK-II President Markus Strobel said the advert was part of "a global campaign to inspire and empower women to shape their destiny".

"The film brings light to the real-life issue of talented and brave Chinese women feeling pressured to get married before they turn 27, for fear of being labelled 'sheng nu'".

He also said the company was adopting "a positive approach in helping women face pressures".

Heavy pressures from society

By government definition, a "leftover woman" refers to any unmarried female above the age of 27.

China's ruling Communist Party tries to urge single women to marry, to offset a huge gender imbalance caused by the recently ended one-child policy.

But according to Leta Hong Fincher, author of "Leftover Women: The Resurgence of Gender Inequality in China", single Chinese women are at "a real turning point" and many are beginning to embrace a single lifestyle and push back the stigma.

She told the BBC: "These are young women with strength and confidence, who are being specifically targeted by the state's deliberate campaign to pressure [them] into marrying.

'She's not too pretty, that's why she's leftover' - The heartbreaking exchange between this woman and her mother. Photo: SK-II/BBC.

Chinese women today are more educated than ever before and they are increasingly resisting marriage."

Hong Fincher, who had a small consulting role in the video, said what made it particularly powerful was that it depicted "the actual state" of women in the country.

"This is the reality and it was told in a very creative, moving and empowering way: that these women are leading great lives in many ways, in being single," she said.

"But the torture experienced by the women in holding out against intense marriage pressure is also extremely real. It reflects the reality of so many young women professionals in China."

'An unmarried woman is incomplete'

At the heart of the video is heartfelt testimony from the women themselves, with some breaking down when relating difficulties they face being single.

"In Chinese culture, respecting your parents is the most important quality. And not getting married is like the biggest sign of disrespect," shared one woman, who later broke down in tears.

Another woman said: "People think that in Chinese society, an unmarried woman is incomplete."

The tough stances of the parents were also featured prominently.

"We always thought our daughter had a great personality. But she's just average-looking, not too pretty. That's why she's leftover," said one mother, who sat next to her daughter who tried to fight back tears.

But the video has proven popular online, resonating strongly with thousands of social media users.

A YouTube video uploaded on the brand's official channel drew more than 350,000 global views and was shared widely among Facebook users.

In China, the video received more than 4,000 likes and was shared close to 20,000 times on SK-II's official Sina Weibo account.

It drew huge praise from vocal netizens on the popular micro-blogging site and prompted a serious discussion.

"Every woman's choice should be respected in civilised society," commented Weibo user Lotus Seed Core.

Cecilia Leung from Beijing commented: "I am a single girl and I needed to see this ad, to tell me that I am not alone and I am not wrong for my choices. One can be happy without a man, and we shouldn't be punished for our choices in life when we have not wronged others."

Another user had this to share: "Age is only a number and should not be used to gauge everyone's goals in life, it's different. To sisters who have yet to meet their soul-mates, don't give up hope and listen only to your heart. Not even your parents, for only you know what is right for yourself. And if you don't, do not grieve but celebrate your life."

Ending on a positive note, the advert sees the single women and their parents visiting a "marriage market".

These "markets" are usually a place for parents to leave posters listing the details of their unmarried children, in the hopes of finding a match.

However, in this case, the parents are shown posters of their daughters, with positive messages for their parents.

In one poster, a woman tells her parents: "I don't want to get married just for the sake of marriage. I won't be happy that way."

"I am opposed to the term 'leftover woman'," says another, with her mother adding: "The 'leftover men' need to try harder."

'Only the beginning'

But can the single women of China see real happy endings - where society will truly accept their choices?

"At the moment, that is only a fantasy," says  Hong Fincher, adding that the "incredible angst, personal torture and societal pressures" depicted in the advert are still prevalent.

"Marriage in China is extremely patriarchal and women need to see that being single is something to be celebrated, not to be ashamed of," she says.

"But I believe that this trend of women who choose to be single and independent is going to increase and this is the beginning."