Shao Bin
A hard worker who is disenfranchised and abused by middle management at a factory. His bosses are responsible for helping him to have a sensible living arrangement, but even though he shares a small one-bedroom apartment with his wife and child, and even though they're giving away free apartment upgrades, and even though they know he needs a new space, they pass over him in their promotions. He takes his case public and takes the case to court in Beijing.
Bin's wife.
Shao Bin is married to his wife who raises their young daughter in their small apartment. Her life is incredibly stressful, and Shao Bin's bosses don't understand what life is like for her—they only mistreat Shao Bin for being less easy to boss around (basically), and this woman is made to live in the consequences. So, she urges her husband to take legal action, since they are literally disenfranchised.
Liu and Ma
These two middle managers work above Bin in the fertilizer factory, and they mistreat their workers. When they realize that Bin is more thoughtful and less easy to boss around, they mistreat him in many small, inconvenient ways. Eventually, Bin gets promoted above them as a response to public scrutiny.