At first glance, the bespectacled 25-year-old might look like proof that China’s education remains a powerful social equaliser.

But a closer examination of Mu’s path shows the field of education heavily tilted away from rural students and toward the wealthy urban elite, part of the widening economic and social inequalities in modern, rapidly growing China. Supposedly socialist, China has compulsory education through grade 9 but not without costs for rural families. Some endure heart-breaking sacrifice to educate their children.

Mu’s own family was so poor that his equally bright older brother had to drop out from sixth grade so Mu could stay in class.

He studied extra hard - sometimes by streetlamp - but his advance was hamstrung by a system that spends several times more per student in Beijing than in Tiaohuashan. His chances of entering a top-notch university were further handicapped by quotas that overwhelmingly favour big-city students.

Mu is the only person from his village ever to make it to graduate school. Only about 3 per cent of impoverished rural students in China even make it as far as college, a Stanford University study estimates. About 84 per cent of high school students in the thriving city of Shanghai advance to colleges, according to Shanghai’s government.

China’s top education officials acknowledge inequities and pledge to narrow the gaps by extending more financial resources to rural teachers and students. Some top universities suggest they will give rural students a break in test scores for admissions.

“Countless people have fallen on this road,” Mu said. “It’s a miracle that I even attended middle school.”

The third of three sons, Mu was born in 1988 in the mountainous southern province of Guizhou, for years China’s poorest with per-capita GDP of US$3,100 (HK$24,000) last year.

He grew up in Tiaohuashan, where hay and manure litter narrow alleyways, water buffaloes bathe in muddy creeks and locals offer incense to earth deities to pray for harvests. His father supplemented farming with a scrap-metal business. His mother was illiterate but had an unwavering belief in education. Their home was built above the stable to protect valuable animals from theft.

As a boy, Mu cut hay and herded cows. He didn’t start school until age 7, and his 9-year-old brother repeated the first grade to join him in class. Three years later, the Mu brothers moved to a larger school with children from several villages.

Discipline was lax. Boys began to drink, smoke and chase girls at age 10, Mu and his friends recalled. Boys pried the legs off classroom benches to brandish in a scuffle. “The teachers could not control us,” Mu said.

Per-student funding in Mu’s province in 1998, when he was in fourth grade, was US$34 a year, compared with US$211 for Beijing. Spending has since increased, but the gap remains. In 2011, per-student funding was US$552 in Guizhou and US$2,985 in Beijing, according to Education Ministry figures.

In 2001, the Mu family’s luck went sour. They lost much of their livestock, and money from some scrap-metal deals was stolen. Paying tuition - about 150 yuan (about HK$190) per semester - for all three boys became out of the question.

The oldest son, then in eighth grade, already had lost interest in studying, but both Mu Zhengwu and the second-oldest brother, Mu Zhengwen, wanted to stay in school.

Mu Zhengwen offered to sacrifice.

“I am older, so I should step back,” he recalled in an interview. “If I had insisted, neither of us would have had school to go to.”

Although lower grade schools were compulsory, tuition fees at that time put education all but out of reach for some impoverished families. Grades 1 through 9 became tuition-free in 2008, but costs for textbooks remained. And China has closed many village schools and consolidated them into regional hubs, which has added costs for travel and boarding, resulting in even higher rural dropout rates.

Mu Zhengwu’s father was too ashamed to borrow money, so his mother searched for and found a creditor willing to lend 300 yuan at 2 per cent monthly interest for Mu’s annual school fee.

He enrolled at the No. 9 Middle School on the outskirts of the city of Anshun in 2001. He boarded there, living on steamed rice and pickled vegetables with a weekly budget of 10 yuan. Malnourished, Mu came down with tuberculosis after one semester. With burning lungs, he returned home to recover before resuming school the following fall.

Teachers at No. 9 resorted to corporal punishment because the mostly rural kids there “were too naughty, and there were many distractions in the city, such as billboards, arcade games and pranks,” Mu said.

Believing that education was his way out, Mu set his sights on the city’s best high school: Anshun No. 2. Well-off families could buy a slot there, but for Mu, testing into it was the only option.

But he was at another disadvantage. At Mu’s middle school, some teachers didn’t even speak standard Chinese, let alone have proper credentials to teach English, Mu said. Without money for tutoring, a computer or study aids, Mu simply pored over his English textbooks.

“Every night, I recited the textbooks under the lamppost on campus. I would be up until 1 or 2am,” Mu said.

Mu Zhengwu was admitted to Anshun No. 2 in 2005, joined by only one of his 40-plus Tiaohuashan peers.

He recalled the stares on his first day of high school, when his mother accompanied him to register dressed in an embroidered cotton dress with a waist sash - a traditional costume out of fashion for decades.

He was behind urban classmates in his studies as well. Mu moved off campus so he could avoid its mandatory power turnoff and study a few extra hours per night. “Compared to city students, we must work twice or three times harder,” said Mu, who had to help with farm work on weekends.

Mu’s high school expenses were more than 10,000 yuan per year. China’s compulsory education does not cover grades 10 through 12, and their tuition rates are the world’s most expensive on average, according to Stanford’s rural education program.

His middle brother again stepped up. Mu Zhengwen was earning several hundred yuan a month in a tire factory, and he gave his younger brother about 100 yuan per week.

To do that, he skipped breakfast, avoided socialising and bought new clothes only when old ones wore out. When his sweetheart learned of these obligations, she backed out of their marriage plans, something he says he never regretted.

“Everything I have done for my brother, I have done it willingly,” he said during a late-night interview at a pastry shop near his current job, at a textile factory in the eastern city of Hangzhou. He spends 12 hours a day overseeing deafening mechanised looms on a muggy floor.

He has a wife now, and a son. But tears filled his eyes when he spoke of his own interrupted schooling.

“I blamed my parents. Why did they have a third child when it was enough for them to have two?” Bending over, he wept silently for a while.

Mu Zhengwu remained diligent at Anshun No. 2. In 2008, he scored 605 in the “gaokao” college entrance exam, far above the 566-point requirement for China’s tier-one universities. He was accepted by Chongqing’s prestigious Southwest University of Political Science and Law. Had he been a Beijing student, he would have landed in the even-more-prestigious Tsinghua or Peking universities.

His annual expenses in Chongqing were about 15,000 yuan. Mu took out student loans. His parents borrowed money from relatives and even fibbed to the government to take out a small agri-business loan.

He still had less money than his urban peers, and it took time to adjust to campus life.

“By the end of the freshman year, everyone in my class had a laptop computer, except me and another rural student,” Mu said. “The gap between the rich and the poor was so shocking that you naturally started to hate the rich.”

The percentage of rural students in college is growing because China has encouraged the growth of independent and polytechnic colleges and lowered the threshold for admission. But scholars say students in these new schools pay twice or three times more in tuition, receive inferior education and end up with less-competitive diplomas.

The top schools still overwhelmingly favour local, urban students. At Shanghai’s Fudan University, for every 10,000 eligible applicants from Shanghai, the school chose 117. For every 10,000 applicants nationally, the school chose two, according to a study by legal scholar Zhang Qianfan.

Mu’s greatest success came last year, when he was admitted into the graduate law programme at Beijing Institute of Technology. Mu received full state funding, and his family has begun to repay debts.

Mu helped by sending home 2,500 yuan from a summer teaching gig. During a visit home, though, his 53-year-old father chided him for that.

“I don’t want him to make money,” Mu Qingdeng said. The elder Mu sat on a sofa covered with a green-and-yellow checkered John Deere blanket, two cigarettes held stored between leathery fingers. His skin was tanned and his nails bruised from decades of hard labour, in contrast to his youngest son’s fair skin and scholarly look.

“He should study hard and go overseas,” the father said. “I want him to create happiness for mankind.”

His mother - with a grandchild strapped to her back - chopped vegetables and mixed sauces for a family dinner. With a guest from faraway, the dinner had drawn neighbours and everyone in the family.

Everyone except Mu Zhengwen, still living and working in Hangzhou with his wife.

“I owe it to my second son,” the father said. Mu Zhengwu said he hopes one day to give his brother the education he sacrificed.

But that’s not going to happen.

“It is impossible, and I don’t want it either,” the second brother said. “I will do my best to make money for my 2-year-old boy so he would get an education. I will work every day that I can.”