Their bed frames were hung with printed sheets and on the walls were posters of Cantonese pop stars, landscapes and kittens in baskets. The room had no kitchen, air conditioning, or even drawers.
"Most of these young migrant workers left homes in the rural villages at about 15 years old and travelled to Guangdong to look for jobs in the factories," Alexandra Harney, an American-born Hong Kong resident, says.
She met the girls of Room 817 while working as a local correspondent for the Financial Times newspaper. The world of the poor factory workers captivated her and became part of her book The China Price.
"I thought, we're probably wearing or carrying something - clothes, shoes, electronics - that they make, and yet no one knew about [these young women]."
From 2004 to 2007 Harney returned repeatedly to the dorm to listen to the young women's stories. They told her about their 14-to-18-hour shifts on an assembly line which earned them only US 17 cents (about HK$1.30) per piece of work done to a sweater. They explained that their wages were cut for every single minute they were late for work, and they even needed permission to go to the toilet.
"They're treated as sub-humans [in the factory]," says Harney, who is now a freelance writer. Her book was published in March 2008, but Harney still keeps in touch with several girls.
One is Li Luyuan, from Jiangxi province (), a cheerful young woman. "She always greeted me with a loud 'Hello!'" the writer says. "Her parents are farmers, but her brother and cousins are all immigrant workers. She struck me as someone who wanted something more in life."
Luyuan dropped out of junior high school because her family could not afford it. At 15, she was sent to join her brother in the city to work there. She started out making DVD parts, then moved on to stitching.
Eventually she saved up enough to buy her parents a modest house back home. After two years in the textile factory, she quit and started working for a real estate agency across the street.
"Luyuan was not concerned only about making money," Harney says. "She constantly said to me, 'I want freedom!' Unlike their parents, many second-generation migrant workers want autonomy and dignity. Luyuan doesn't want just to clock in and out of a factory for the rest of her life."
Working as an estate agent gave Luyuan a taste of freedom and a better quality of life. But her bliss lasted only two years - until the Shenzhen estate market collapsed. The young woman moved to Shanghai, where she opened a fruit store with a friend. That didn't work out, either. Finally she returned to Shenzhen to look for work there again.
Like the 150 million other migrant workers on the mainland, Luyuan had to change jobs often just to make ends meet. "The story of Luyuan and many of these young migrant workers has changed my way of looking at China and the global economy," Harney says.
"They are a huge, productive force of our global economy. What they want is independence and a future. But the companies who hire them are not interested in training them," she explains. "I find it perverse how the global economy has separated us from those who produce for us every day. Our appetite for 'close to zero' cheap products is keeping these teenagers working past midnight in illegal, dusty factories. Their stories will allow us to understand how human lives are altered by excessive consumption."
The lives of these migrant girls have inspired Harney to start up a social enterprise project: Bus to Success.
The project, still in its initial stages, will be a mobile education centre on a bus. With its help, young women can learn practical skills and train in entrepreneurship. They can choose what new skills they want to learn.
"I want to help them create a better future for themselves," Harney says. "I want to show people these girls are capable of doing more with their lives."