Today, that initial effort has evolved into Kardan University, a private institution educating more than 8,000 students in programs ranging from political science to civil engineering. But for Rahmani, the school's chancellor, it's not enough.
"My vision is bigger than this," he says.
Rahmani's dreams of growth could easily come true if Afghanistan doesn't fall apart after foreign forces complete their withdrawal next year. Demand for higher education is soaring in the war-weary country, a striking vote of confidence in its future.
It's a remarkable trend in a nation where just 12 years ago the Taliban government barred girls from attending school and many educated Afghans were forced to flee. Some 7,870 students attended Afghan colleges before the U.S.-led invasion in 2001; today, the figure is up around 26-fold to almost 204,000, as many as a fifth of them women, according to the Ministry of Higher Education.
The growth has been possible in part because Afghan leaders realized that the country's public universities, decimated by years of war, couldn't meet the demand for seats. So in 2006 they legalized private higher education.
Today, 70 private institutions of higher education operate in Afghanistan, educating about 74,000 students, or more than a third of the total, according to the ministry. Many are like Kardan, set up by businessmen with little or no background in academia. Some are backed by foreign governments striving for influence here, and at least one is run by an ex-Taliban leader.
Education authorities say steps are being taken to ensure that the private schools are not merely money-making schemes. But even critics agree that a thriving private sector is crucial for education in this country of 30 million people, two-thirds of whom are 24 or younger.
"In developing countries, especially, you need to invest in higher education, because the need for leadership is so great," said C. Michael Smith, president of the American University of Afghanistan, a private nonprofit institution with more than 1,000 students. "You need a strong government sector, and you need a strong private sector."
Young women in skinny jeans and colorful headscarves take notes alongside young men with modishly spiked hair. Fliers post notices for extracurricular activities. Teachers recruited from Pakistan, India and farther afield add something of an international flavor.
There's no campus quad or sports stadium — it's basically an office building — but the energy coursing through the halls is palpable.
Katia Mohib, a shy, slender 22-year-old, is finishing a business administration degree. Like many of her fellow classmates, she didn't score well enough on Afghanistan's highly competitive college entrance exam to land a spot in a public university, so she chose Kardan.
"I am very happy," Mohib says. "I am sure that after I finish I will be able to work for a good organization."
The driving force behind Kardan is Rahmani, a wiry man who, being just 31, sports a goatee lest any members of the academic establishment judge him too young for his job. His founding partners have parted ways, but Rahmani has recruited a staff of other young, energetic Afghans.
Rahmani spent much of his childhood as a refugee in neighboring Pakistan. He says he has multiple business degrees — one is an MBA from the York University Schulich School of Business in Canada, where he has lived on and off.
Rahmani says Kardan has a $4 million operating budget, and charges around $6,600 for a four-year bachelor's degree. The students, many of whom have jobs, can pay monthly.
The school's rapid rise has prompted questions about whether it is producing qualified graduates or suckering students out of their money.
None of its critics would go on the record, but Rahmani says their suspicions are misplaced, and that all profits are invested back into the school. "I've read people calling me a drug dealer, mafia, stuff like that, but I'm happy I'm not involved in any of those things," he said.
Rahmani acknowledged that some of Kardan's programs need more academic rigor but predicted standards would improve with time. He said that if private universities operating in a war zone had to meet Western standards, countless Afghans would never get a college degree.
"We need to get going, otherwise we can't get anywhere," Rahmani said.
Of course, few ordinary Afghans can afford any type of college, especially in the rural areas where illiteracy and poverty are rampant. Even the 31 public universities, which don't charge tuition, are unaffordable for many due to side costs such as transportation and textbook fees.
Afghanistan's public universities themselves would struggle to meet the standards of higher educational institutions in more developed countries. Only about 5 percent of their faculty members have Ph.D.s, and just over a third have master's degrees, while there are only two authorized doctoral programs in the entire country, according to the ministry.
It did not have the figures for the private sector, but it's not unusual to find teachers in their 20s at places like Kardan.
Last year, the ministry launched an accreditation system for all colleges. For now, getting accredited is a voluntary process, but it will be mandatory in the coming years, said Fred Hayward, a U.S. adviser to the ministry. The drawn-out timeline gives schools a chance to improve themselves.
"The goal is not to shut down higher education institutions. The goal is to make them better," Hayward said.
Kardan — the name means "professional" — is big competition for the public colleges, but so are the increasing number of other private institutions, some of which promote religious ideologies, national interests or both.
Iran's Islamic Azad University has a campus in Kabul, believed to be one of several Iranian-funded colleges in Afghanistan. Afghan and Arab media have reported that Saudi Arabia is planning to build a massive Islamic center in Kabul that includes a university.
The American University of Afghanistan, considered one of the best in the country, operates primarily on a two-hectare (five-acre) campus in Kabul and is developing an additional 32 hectares (80 acres) across the street as well as branches in other cities.
Then there's the Afghan Institute of Higher Education. It is led by Wakil Ahmed Muttawakil, who in the 1990s served as a foreign minister under the Taliban government.
Around 55 of the institute's 360 students are women, and classes are gender-segregated, though men teach some women's classes because of a lack of female staff. Its programs include business administration and Islamic studies.
Abdul Jabbar Baheer, a school administrator, dismissed the notion that the Taliban would frown on admitting women. He said the movement wanted all students to be educated within a religious framework, but that when the Taliban ruled, their government lacked the funds to educate women as well as men.
Whether the Taliban will return to power is a question that looms large here. As U.S.-led troops reduce their presence, with a full exit planned by the end of 2014, Taliban insurgents have stepped up attacks across the country.
But Afghan college students were upbeat, even defiant, about pursuing their dreams in spite of the uncertainty.
Kardan student Liza Ormol has a 10-year academic plan. During that period, she intends to obtain a bachelor's degree in business, two master's degrees and a Ph.D.
"I am a very positive-thinking person," the 19-year-old said. "I believe what I am doing is best for me and my country."