Even at the age of 7, Ripton Rosen was obsessed with baseball. So he was thrilled when a group of 12-year-old boys in a Lower East Side Manhattan park allowed him to join in their game one steamy summer evening in 1998. His teammates, like most of the residents in the neighbourhood at the time, were black or Latino. Ripton's parents and 5-year-old brother, Morgan, were white and lived in the penthouse of a renovated upscale building across the street.

At game's end, flushed and exhilarated, Ripton shouted out, "Who wants to come play Nintendo 64?" It was the hot game system that year, and about a dozen sweaty boys quickly followed him across Avenue B. Michael Rosen, a Wall Street CEO at the time, and his wife, Leslie Gruss, a doctor, were momentarily startled but then warmly welcomed the kids into their 16th-floor penthouse. "We had moved to the neighbourhood for ethnic and economic diversity," says Rosen, "and you don't say no when diversity walks in the front door."

Years later, Will Torres can recount his first moments in the penthouse in detail. "In we come, and the first thing I see is Leslie standing in the kitchen like a mother on a television show," he says. "She's smiling and asking, 'Do you guys want some cookies?' And I'm not even believing it. I'm thinking, Wow, these people are so white!"

One big family
None of the young players, who had all grown up in cramped, overcrowded flats, had seen anything like the Rosens' home, with its sprawling floor plan spanning five levels. Terraces offered breathtaking views of the East River and the Empire State Building, as well as a place to grow strawberries in the spring; at night, the New York City skyline lit up the rooms. Inside were four aquariums teeming with tropical fish, a huge fridge packed with litres of milk and juice, and kitchen shelves spilling over with jumbo boxes of multiple snack choices. "It was like a dream to me," says Kindu Jones.

As summer turned to autumn, the baseball games continued, and several of the boys became frequent visitors to the Rosens' home. In time, the group evolved into five regulars: Will and Kindu, Philippe Medina, Juan Carlos Robinson and Carlos Suarez. Ripton and Morgan, who attended private school on the Upper West Side, were happy to have friends in the neighbourhood. The age difference presented no problem. Almost from the beginning, they viewed the "big boys" – as they are still called – as their brothers.

"It happened gradually and normally," says Leslie, who without thinking about it began purchasing larger containers of Gatorade sports drink and chips. "When the boys walked into our lives, it was like a breath of fresh air."

The Rosens' soaring living room became a play space where the kids would stack cushions into soft mountains to leap onto from a balcony. For their informal wrestling matches, Leslie purchased gaudy World Wrestling Federation belts; Michael bought baseball gloves for those who didn't have their own. And on weekend nights, when the group slept over, they turned out all the lights, picked teams, and played a game with plastic pistols and flashlights. Leslie and Michael would sit in the dark, monitoring the action. Without planning it, they were becoming an extended family. "We came to eat and have fun," says Carlos Suarez, who had known little of the latter in his short life. He remembers seeing his father murdered right in front of him when he was 11.

"It was Good Friday," he begins, his voice rising, "and we had just bought ice cream – vanilla with sprinkles. This guy my mother knew threw a cup of alcohol into my father's face, then took out a screwdriver and stabbed him in the heart four times." The family subsequently spent months in a couple of rough homeless shelters before settling in the Jacob Riis projects, a few blocks from the Rosens' penthouse.

Kindu, who says his mother died of Aids, lived with 5 brothers and 3 sisters. Most of the other boys were being raised by single mothers struggling against daunting odds. Drug dealing and poverty were part of their everyday landscape. Relatives had been in and out of jail.

The Rosens came from a separate universe. Michael, the son of an accountant, had grown up in Vermont, where he learnt to ski at the age of 7. In 1975, he enrolled in the University of Pennsylvania, where he soon met Leslie Gruss, the daughter of an investment banker with a seat on the New York Stock Exchange. Raised on East 79th Street in a spacious, art-filled flat, she had attended private schools and decided in the 8th grade to become a doctor. Michael left Penn with graduate degrees in anthropology and business and joined the faculty of New York University business school. Leslie qualified as a doctor at the Medical College of Pennsylvania, and the two were married in 1983 at a Vermont country inn.

Five years later, Michael left teaching to develop one of the first luxury rental buildings on the Lower East Side, on property owned by Leslie's family. He fell in love with the rich cultural and social mix of the neighbourhood, where waves of immigrants had settled since the early 19th century. The Rosens purchased their penthouse in a former settlement house that had been converted into townhouses. At the time, Tompkins Square Park, across the street, was teeming with homeless people living in makeshift shacks. When Leslie spotted a flock of pigeons nesting in an area of the townhouse that Michael said would be their master bedroom, she says, she thought her husband had lost his mind.

In 1991, when the family moved in, Ripton, who was adopted as an infant, was 6 months old. Morgan, also adopted, joined the family 2 years later. Soon the park was closed, to be renovated into an urban showplace of playgrounds and green space. Michael made significant money in Lower East Side real estate before moving to Wall Street, and Leslie joined an ob-gyn practice in SoHo. The family enjoyed ski holidays in the winter and spent summers on Shelter Island.

Learning to learn
The 5 boys who came to play video games reshuffled everything. "In the beginning, it was just a lot of kids swarming all over the place," says Michael. Things then began shifting in small ways. When the Rosens realised Carlos wasn't attending school because he didn't have suitable clothes, they bought him some. Then one night, they took the group to a bookshop after a Chinese dinner and realised there were other needs. "The boys had no interest in books at all," Michael says. Back at the penthouse, he insisted they sit down to read aloud. "Their vocabularies were limited," he says. "But my concept of what is smart and what is not changed that night, because these kids were all smart but also uneducated."

The boys still typically slept at their homes, though they spent after-school hours, most weekends and summer nights at the penthouse. There, a half-hour reading period before video games or television was instituted. The kitchen timer was set, and everyone had to circle the words they didn't know. One summer, Michael took all the boys to the library; each got a card and picked a subject to study. Will, Michael remembers, chose bodybuilding. The subject didn't matter; reading did. A poet friend of the Rosens' suggested buying copies of Moby Dick and reading it together around the dining-room table. "Well, it was a nightmare," admits Michael.
"That book is not written in a language these kids speak. But we kept pushing and pushing."
Slowly the big boys became an integral part of the Rosen household, even helping to light the candles at Hanukkah. Chores were assigned, including cleaning, loading the dishwasher and walking Mr Jenkins, the family dog. Arguments broke out when rules were ignored; it was never a scene from The Brady Bunch.

The boys' own families were puzzled by what was transpiring. "My mum didn't believe me when I told her about the penthouse," says Kindu. "She thought I was involved with something bad." Juan Carlos's mother, Esther Ruiz, wondered, Why would the Rosens be doing this? But as time went on, she noticed changes in her son. "It wasn't just the streets anymore. He was getting responsible. Michael and Leslie are the best."

"We had questions ourselves about what we were doing," confesses Leslie. "Were we shortchanging our own children? We were definitely concerned about the example the big boys were showing, but in the end, I think the notion of actually helping people is of greater value than anything else."

Adds Michael, "We felt our decisions had real consequences. If these boys started to go in the wrong direction, they could die." Michael and Leslie became determined to see that they all go to university.

Then, in 2000, the Rosens separated. "It's hard to put your finger on what causes such things," says Michael, but he insists it had nothing to do with the boys, who responded by assuming true big-brother roles. "It was a tough time for Ripton and Morgan, and we helped them get through it," says Kindu. "We kept telling them that Michael and Leslie were going to get back together, and eventually they did." The summer the Rosens reconciled after 2 years apart, Michael took Leslie, Ripton and Morgan to China and Vietnam for three weeks. While there, they telephoned Kindu, then 17, and asked him to move into the penthouse and take care of things for them.

It was a turning point. "This was a leap across boundaries to trusting someone the way you trust family," says Michael. They were now permanently bonded. The boys would never be officially adopted, but they would always be sons to Michael and Leslie.

Just the beginning
As university application time approached, it turned out some of the boys had misrepresented their academic performance to the Rosens. Michael gathered them for a summit none has forgotten. "I want you to have a future," he declared. "I don't want you to end up on the street." Carlos, who'd been avoiding school altogether, moved into the penthouse and enrolled in an educational centre called The Door to get his GED (General Educational Development).

Phil, who needed 12 credits to graduate, also moved in. "Leslie would sit me down with a laptop and make me do all the homework for my classes," he says. "Sometimes it would take 8 hours." One course required a museum visit. Leslie enlisted her mother, a volunteer at the Metropolitan Museum of Art. The first sentence of Phil's subsequent report – "I went to the Metropolitan with my grandmother, which is an art expert" – still makes her smile.

Today, Carlos refers to Michael as his white pops, and Michael has overheard him in phone conversations saying, "I was just talking to my dad about that." When Carlos won a baseball scholarship to St Charles Community College in Missouri, his player biography listed three parents: "Evelyn Velez, Michael Rosen and Leslie Gruss."

Kindu recently graduated with an associate's degree from Morrisville State College, and Phil is at Mohawk Valley Community College in Utica. Will and Juan Carlos attended Borough of Manhattan Community College. Now teens, Ripton and Morgan are pupils at Brooklyn Friends School. Ripton still dreams of being a baseball player and hopes to go to Arizona State. Morgan is involved in extreme skateboarding. "I have friends who are single children," he says, "and I see how dull their lives are and am thankful for what we have."

It is not a life either of the Rosens imagined. "You meet some kids in the park," says Leslie, "and life unfolds, and they become part of your family. Parent-child love grows from caring. You know, I feel protected by these boys. They put their arms around me with that macho, I'm-gonna-take-care-of-you-forever thing. I thank them because they changed my life in many important ways."

"I don't think I would have become the man I am becoming if I wasn't in the Rosen family," says Phil. "It's not just Mike and Leslie and Ripton and Morgan. It's the others, too; it's having the same friends for so long. I have a black brother and a white brother, and I tell everybody I'm half-Jewish.
People do a double take, and I say, 'It's a long story.' It's a beautiful situation. We all just click."

On a recent weekend, all the boys were home for a surprise 50th birthday party for Leslie. Once again, the television was blasting, music was blaring, jackets and laptops were strewn all over the penthouse, and everyone was fighting about food left out of the fridge, mislaid athletic equipment and whose turn it was to walk the dog. When the time came to leave, Leslie urged the boys to make sandwiches instead of stopping on the road, and Michael complained about the late start and opened his wallet for petrol money. There were hugs, kisses and shouts of "Bye, guys! Study! Drive carefully. Love you! Study!"

"There's a lot of love in this family, no matter what," says Kindu. "This is for life."