Kim Kardashian stretches toward the ceiling with everything she has. Her arms and fingers extend up, her chest rises, and her voice moves into an upper register. "I do, I do!" she cries. She's in the living room of her mother's house in an L.A. suburb called Hidden Hills; she's 27, but her body language and intonation are those of a child who's been asked "Who wants ice cream?" The actual question, as posed by her mother, was "Who wants to watch it again?"

There are four Kardashians in the room--Kim, her sisters Khloe and Kourtney, and their mother, Kris--and one Jenner, Bruce. To be accurate, Kris has been a Jenner since 1991, but she's as tawny and kohl-eyed as her daughters, and her fishnets and stiletto heels suggest that she wouldn't mind being mistaken for one of them. The quintet have just finished taping a segment for the morning show Good Day LA, to promote their new E! Network reality show, Keeping Up With the Kardashians. Kris cues up the TiVo, and we all stand around and watch the clip. The show's cohost Jillian Barberie is a longtime friend of the family, so the segment revolves largely around a few gambits: It's about time the Kardashian family had a reality show! Kris looks sooooo young! Bruce Jenner lives in a house full of craaaaazy women! You're probably asking yourself a few questions at this point. Who are these Kardashians we're supposed to be keeping up with? Didn't one of them make that sex tape? What's Bruce Jenner doing here? But if you really wanted to get to the bottom of things, you'd hang out with Kim while there were cameras around--which is pretty much all the time.

The past year in entertainment was notable for many reasons, not the least of which was Kim Kardashian's rise to prominence as the sublime embodiment of L.A.'s pseudo-celebrity cottage industry. She's known Paris Hilton since childhood, and counts among her closest friends reality starlet Nicole Richie. Kim's sister Kourtney has appeared on a small-screen, L.A.-scion version of City Slickers called Filthy Rich: Cattle Drive; her stepbrothers Brody and Brandon Jenner were lovingly documented on another rarefied-heirs show, The Princes of Malibu (Brody has since elevated parasitism to heights Kato Kaelin never dreamed of, insinuating himself into every MTV soap opera imaginable). Until the release of a certain film last spring, the closest Kim had come to visibility was briefly dating Nick Lachey.

But about a year ago, people started asking, "Who is that hot-ass girl who's always standing near Paris Hilton?" And then a sex tape of Kim with an ex-boyfriend--R&B singer, aspiring cinematographer, and Brandy's brother Ray J--surfaced. It was at this point that the gossip blogs became transfixed by a woman whose distinguishing features seemed to be that (1) her father, Robert, was one of O.J. Simpson's defense attorneys and (2) she was so curvy that bloggers could not be convinced that her ass wasn't fake.

TMZ dubbed her The Tush. People devoted an article to her ass. So did the magazine King, though that's less surprising (what is surprising is that she was the first white cover model in its six-year history). Kim is something of a photo-negative Venus Hottentot, the elusive White Girl With Physics-Defying Buttocks. According to her, she developed early and was a C cup by age 11, with similar topographical shifts south of the border. "I would cry about it," she says. "I swear, I would say my prayers at night, hoping that I would stop developing." In her adulthood, things changed. "I've embraced it," she says. A few months ago she unveiled something that can only be called a Signature Angle. It's kind of a three-quarter turn, Kim smiling coyly back at the camera. You can see it in the tabloids. You can see it in web videos, in which the paparazzi shout their requests: "Kim, Kim, over the shoulder!"

Thanks in large part to that well-bejunked trunk, Kim's 15-minute empire is slowly, inexorably coming together. There's the television show, a Meet the Osbournes minus the complex characters, executive-produced by Ryan Seacrest and relentlessly hyped by E! commercials. There's the Playboy spread. ("My mom was like, 'Wow. If I had pictures from when I was your age . . . You should do this while you can. They might never ask you again.'") The calls from cable networks, from Adam Sandler's people. Today alone, Kim has two TV segments to tape, a fashion shoot for a magazine, and the show's premiere party. After the TiVo'd clip ends, she leaves to change outfits.

While she's gone, Bruce Jenner talks about taping episodes of a new reality show called Jury Duty. The concept seems to be that people agree to settle their legal disputes via a panel of quasi-celebrities. "I did it with Paula Poundstone," he says. "She is an ab-so-lute riot." He still has the 1977 Wheaties-box haircut, and his face is wrinkle-free in a way that seems unlikely.

Kim comes back into the room in a sweat suit and a deep-V-neck T-shirt. She heads out the door to her white Range Rover (the words range rover on the back have been custom-painted pink) and drives the 10 minutes to Dash, the Calabasas clothing boutique that she owns with her sisters. Kim's also a professional closet organizer. "There is a huge misconception of Hollywood girls," she says. "That we don't work, and we're just famous for being famous." Though, of course, she is. Inside Dash, the girls prepare to tape another segment for the morning show--something about "hot looks for fall." A table in the middle of the room displays some non-apparel items: Nicole Richie's "novel," The Truth About Diamonds; a Taschen book about Marilyn Monroe; a novelty striptease kit. It's like the impulse-buy version of Kim's id.

Kim goes into a dressing room to change, while Khloe and Kourtney (23 and 28, respectively) start talking about hot looks for fall. To see them together is to wonder how Kim, with her seemingly unrelenting, innocuous sweetness, is related to them. They're both lively and sarcastic; they mug, they flit, they slap each other on the ass. Khloe fingers a dress for the camera. "This one gives you the cleavage without all the boo-tay," she says. "Can't give it all up, girl!" She pauses. "Well, if you talk to me, I will." When Kim comes out of the dressing room, Khloe says, "Obviously, Kim dresses a little whorey at times."

Kim smiles uncomfortably. "Khloe, don't talk like that," she says.

"Kim, just because you have a stick up your ass doesn't mean we can't have fun," Khloe says.

"You say I have a stick up my ass every day." Kim turns from her sisters to the cameraman. "They love each other more than me."

She presses on, picking some dresses off the rack. She identifies them by the event she wore them to. This one is the Heatherette fashion show, that one is the T-Mobile ID party. And when they finish taping, Kim tries to decide what to wear to the party that night. She worries that one dress pushes her breasts up too far; as she fusses with her décolletage, the Good Day LA cameraman looks around. "God," he says to no one in particular, "I love my job."

There's a strange dynamic at work here. Kim is someone who should by now have inspired some hate-mongering--or at the very least have been dismissed. There's a groundswell of pop-culture antipathy that has all but engulfed Paris Hilton and her moneyed, insulated, famous-for-nothing breed. So why does it barely lap at Kim's feet? If you watch her in action for long enough, there's one explanation that emerges. In the makeup chair at a photo shoot in West Hollywood, Kim's the same person she was in her parents' house. Sweet, unassuming. She shortens adjectives like any other Valley girl: "Cheese." "Expense." When the first flash goes off, though, something changes. A switch flips; she touches her face, arches her back. She swims through honey, she parts her lips. There are 20 people gathered around her, and the silence is thick.

"I'm not the sex kitten that they've made me out to be," she says. "But I'll kind of give it to them when I have to. I know that's what they want, and so I give it to them."