'See this?" Justin Bieber asks excitedly, turning his head and showing off a fading red pucker on his cheek. "Can you see it?"
"It's Rihanna's kiss," he says. The night before, the 15-year-old Bieber attended a star-packed music-industry party in New York, where he met Bono and got a tender buss from the Barbadian pop siren. "I had a shower and everything – and it's still there."
Welcome to Justin Bieber's adolescent fantasy. Not long ago, the feathery-haired heartthrob was kicking back on his couch in Stratford, Ontario, cooing R&B ballads for fun. Now he's nudging the Jonas Brothers out of the tween locker room with his debut EP, My World (400,000 copies sold so far), and a YouTube following (100 million views) that redefines hormonal idolatry. In November, a Bieber appearance at a Long Island mall resulted in a riot before the singer even arrived. "They threatened to arrest me and my mom if we came," Bieber says, riding in the back of a black SUV from New York to a Philadelphia gig.
Bieber might look like the latest in prepackaged tween catnip, but what's unusual about his rapid ascension is that he's done it without the kind of synergistic TV platform Disney used for Miley and the Jonases. "I get thousands of e-mails every week saying, 'Please don't go Disney,'" says Bieber's manager, Scott "Scooter" Braun. "Kids made Justin. They made the fan pages, they spread the Twitters, they put up videos. I'm a good marketer, but not as good as them."
In the SUV, Bieber stretches his right leg. On his foot is a gray Aircast, the result of a fracture he sustained onstage before Thanksgiving in London, where he was opening for Taylor Swift. "It sucks," he says. "I want to jump and dance. I want to take it off right now, but I can't." He yawns when describing the 15 hours of mandatory tutoring he receives each week. "I don't like sitting there – it's boring," he says. "I want to be in movies like what's her name – she's blond, she's young . . . "
"Dakota Fanning," his assistant says from a front seat.
"Yes! Dakota Fanning. Cool stuff like that."
Right now, Bieber should be in the 10th grade back in Ontario, where he starred in youth hockey and soccer. Bieber's parents split when he was just 10 months old – his father, Jeremy, works in construction in Winnipeg, Manitoba, and remains close to his son. Bieber and his mother, Pattie Mallette, 34, shared an affordable-housing apartment. "It was awful," Mallette says, laughing. "But we had a roof over our head and heat and food most of the time. It's quite different coming where we're coming from to being driven around in limos." Bieber learned to sing by listening to his mom's Boyz II Men records. When he was 12, he began uploading videos of himself performing songs like Ne-Yo's "So Sick" to You-Tube. "Every time I put one up, I got more views, and I started getting calls from people in the record industry," he says. The most persistent calls came from Braun, a well-connected 28-year-old who helped launch the career of "I Love College" rapper Asher Roth. Braun piqued the interest of a pair of superstar friends: Usher and Justin Timberlake, who summoned Bieber to Memphis for an audition. "We walked in, and who greets me at the door but Jessica Biel," Bieber recalls. "And she's like, 'Hello, babe.' Well, she didn't say that – but I was thinking it! I sang 'Cry Me a River,' and we watched March Madness basketball."
But it was Usher – who'd met Bieber in Atlanta when Braun was first courting him – who won out. "He had all the nuances of a classic artist," Usher says. "Very cute, for all the young girls – gotta have that. He had swagger. And most important, he had talent." Bieber signed with Island Def Jam. Working with Usher and producers like Tricky Stewart (Beyonce's "Single Ladies [Put a Ring on It]"), he recorded My World, a sunny splash of radio-ready R&B with unabashedly innocent lyrics. On one cut, "Bigger," Bieber sings, "Now the bullies in the schoolyard/Can't take our hugs and our kisses from us."
A few days later, at the Z100 Jingle Ball at Madison Square Garden, Bieber steals the spotlight from Swift and John Mayer, who jokes, "I'm John Mayer — I'm 52 years old." When Bieber finally takes the stage, the squealing rocks the Garden. Usher shakes his head in amazement. But it can't be a late night for pop's new idol. At 5 a.m., Bieber is jetting to Las Vegas to tape a segment for Dick Clark's New Year's Eve show and to the White House for a Christmas special. "I'm excited," he says. "I guess Obama's daughters like me."
This story is from the January 21st, 2010 issue of Rolling Stone.