At ground level are stored rolls of dark blue denim, produced locally in Guangdong and Zhejiang, and which give off a pungent dyestuff aroma that most locals say they don't even notice anymore.
In a dim second-floor office, a young woman in her 20s was looking at new designs online.
Of her job, Lin Xingxing said: "YZY is the one of the few factories employing a full-time designer. The fashion in jeans changes so fast, I must research the latest trends online and then create them for our customers."
On the passage wall were colorful posters and encouraging catchwords designed by Tang Yue himself.
"Work to buy your house, your car and work for a better life," said one, its red letters bright against a green background.
"I pay attention to management details and am trying my best to transform a workshop into a modern factory, like the ones I worked at in Guangdong," said Tang, who pays his workers according to how many pieces they make.
It takes dozens of different steps to create a pair of jeans from the cloth piled up on the ground floor.
Each step takes about five people to sew the sides together as well as the pockets, waistband, fly, zipper, etc. The semi-finished products are heaped on the floor and carried by hand from one sewing station to the next.
On a recent visit, no sound could be heard but that of about 100 sewing machines all running at top speed. The workers' hands were all dyed blue by the cloth they handle.
"Once the boss gets the product order, we start working like machines," said a worker in her 30s. "We work 10 hours a day at least and make about 2,000 yuan a month at most."
Some children of the women were seen playing on the piles of half-finished jeans in the workshop.
"My husband worked in Guangzhou as a migrant worker, and I do not want to leave my child with his grandparents in the countryside. So I take him to my workplace," a young garment worker said.