THE TEMPERATURE INSIDE A BORROWED CLASSROOM IN Sacramento, Calif., hovers in the 90s. Twenty boys, sitting at their desks, try hard not to disturb the proceedings, but one of them doesn't make it: He spouts out a question without raising his hand. "What, Brother Ernest?" says the tall man at the head of the class, a smile touching the corners of his mouth. "You want to stand by me—like last time?" That, everyone knows, is the ultimate humiliation, and Ernest promptly scrunches down, trying to make himself invisible. That only earns him a second rebuke. "Brother Ernest, sit up straight," says the man. "You've been here two years. Don't act like I'm surprising you."

Meet Kevin Johnson, 25, teacher, disciplinarian, father figure and founder of St. Hope Academy, an after-school program that offers guidance, academic skills and friendship to black youths, 8 to 18, from the drug-ridden Oak Park section of Sacramento where he had grown up. For eight months a year, Johnson, or KJ, as he is called, labors for the Phoenix Suns of the National Basketball Association (last year the all-star, 6'1" guard led the team in scoring and assists). But judging by his 75-hour weeks during the summer off-season, Johnson's first love is St. Hope. I le teaches, he holds rap sessions, he keeps his office door open and hands out his home phone number. Even during the basketball season he calls the boys, just to see how they're doing. "I get more joy from this than anything else," he says. "In the long run, I affect in a positive way the lives of people who would've gone down the wrong avenue."

The program uses six in structors to teach academics as well as values not normally present in dysfunctional families. "They make us do stuff we don't want to do," says 15-year-old Anthony Lambert. "Like when you're tired and don't want to work, they make you do it anyway. It makes you a stronger man." Among the organization's admirers: California Gov. Pete Wilson. "Kevin has never forgotten where he comes from and the people who are still here, looking for every opportunity to better themselves," Wilson says.

Johnson founded St. Hope in 1989 after observing that he was the only one from among his childhood friends to make it out of the neighborhood successfully. "So many people were more talented," he says. "What gave me the desire?" His answer: "It had to do with family support." Young Kevin's support came from his single mother, Georgia, now a nurse, and his grandparents George and Georgia Peat, who helped raise him. He says of his grandparents, "They were two of the best role models anybody could have. They had strong character and values."

And they set tough standards. Kevin excelled academically at the University of California, Berkeley, where he was also the school's all-time career scorer (1,655 points). KJ, who is single, hopes to quit the pros in five years and devote more time to St. Hope. But his organization, partly funded by Johnson (KJ's 1991 salary: $2.1 million), is already burgeoning. This fall, with the opening of its 7,000-square-foot permanent home, it will begin to add six instructors and increase the student body to 50, including, for the first time, girls. "If I can teach [kids] certain values—to be good citizens, to have a positive attitude, to contribute to their communities," says KJ, "then this is the best thing I can do for Sacramento and myself."

—J.T.; JANE FERRELL in Sacramento

Get up-to-the-minute celebrity news and photos on your cellphone, iPhone or Blackberry at www.people.com!