"Another reason is that I don't want anything to upset the apple cart."

Despite the downsides of being lonely, being single means you are free to do whatever you like without considering a girlfriend's or boyfriend's opinions, he says. On the other hand there is no one to turn to as you face the pressures of city living life and the irritants that work throws up. Another bad thing is having no regular sex life, he says.

Apart from having problems finding the ideal person, Chen also attributes delaying getting married to practical problems.

"I'm 33, I don't own a car, and I don't own a house, so I have few chips in the marriage market."

Li Yinhe, a sociologist, says staying single is as much a trend in North America, Europe, and East Asia as it is in China and people in this country are delaying marrying because of "the very high price of divorcing, mentally and financially".

"So many people would rather simply live together and not get married. There are so many responsibilities in marriage, especially when couples bear children. For that you have to sacrifice a lot, and in the main single people have an easier life.

"In addition, the social status of women has improved, so they have jobs with which they can pay their way, which is one important reason why they can delay getting married or just stay single.

In Shanghai the average age for women to first get married was 27 in 2012, and 30 in 2016, Euromonitor International says.

Han in Beijing says she enjoys being single. As a cartoonist, she spends her free time doing her art, watching movies, reading books, exercising, meeting friends, or going for walks, which adds up to "so many things I can do".

"So I don't want a man to undermine my happiness, not to mention getting married or having children. We are the generation of the one-child policy, and we are so used to being alone. For me, living alone is a normal state."

Although they live interesting lives at the moment Chen and Gong acknowledge that they fear aging.

Gong says she once lived through a period of depression after returning from the US in 2014. Unable to work, she had to go back to her hometown in Guizhou province and lived with her parents.

"At the time, I realized how terrible it is to face sickness and death alone," she says.

Chen says: "The biggest worry is my parents. They are getting old and they want me to have children. Then there is the fear of being sick and of dying alone."

However, Li says that as China gradually ages, the aged-care industry is developing. As it grows, worries that single people have about aging will diminish, which means more people can choose to stay single, she says.