"That's dangerous," Shi says.

"If they argue, the bodyguard might be upset and not focus on the client's safety."

They're actually forbidden from having romantic relationships with anyone outside of work, too.

"Women have to be independent," says Lulu, Shi's employee.

Female bodyguards keep threats at arm's length

"Some clients remain single into their 40s. They're outstanding and have many suitors. A woman can lead a happy life even if she doesn't marry young."

Most clients advise Lulu to master as many skills as possible.

One even taught her how to perform tea ceremonies.

"I really like tea ceremonies," Lulu says.

"They've changed me a lot. They've made me more feminine."

Yu and Lulu are from well-off families and say they didn't choose their careers to make money.

Yu says she went into the sector to work alongside successful people and learn things from them that ordinary white-collar individuals don't get the chance to, such as etiquette and industry secrets.

Pan, who has worked as a guard in such countries as Libya and Kuwait, says China's private security industry is chaotic. Some unprofessional agents harm the sector's reputation.

But starting last year, guards who pass qualified trainings can get the Special Security Professional Training Certificate issued by the Ministry of Human Resources and Social Security.

"Such a certificate paves the way for sector regulation," he says.

Given the surging wealth of Chinese women who feel they need private security, it seems likely a mounting slice of the certificates' holders will be female guards.

Tiffany Tan and Erik Nilsson contributed to this story.

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