Called “crackberry” by many of its weight-conscious fans, Pinkberry, a frozen yogurt shop that was launched two years ago in Los Angeles, is on the fast track in New York.

The chain’s founder, Hyekyung “Shelly” Hwang, 32, the daughter of a factory owner in South Korea, has already opened three Pinkberry stores in Manhattan and plans to open 30 locations in New York by the end of next year. So far, her plans seem to be working out well.

Lines at the first Manhattan Pinkberry, in Koreatown, often spill onto 32nd Street, leaving customers waiting up to 20 minutes for a $4.50 cup of yogurt in either plain or green tea flavors, with a fresh fruit topping such as blueberries, kiwi, or mango.

“I was really concerned about the cold weather at first,” the president of Pinkberry, Young Lee, said about opening stores in New York. “But then I saw the line on a very cold day. People get addicted to it. That’s what we count on.”

Food blogs have devoted pages to analyzing the tart flavor and icy texture of Pinkberry’s offerings. In addition, the frozen yogurt purveyor also devotes attention to the design of the store.

Mr. Lee, the designer of Pinkberry, was a bouncer at New York nightclubs before he started constructing them. He wanted Pinkberry to look as clean and fresh as its product, he said. He streamlined the stores using Philippe Starck plastic furniture and Le Klimt lamps and maximized their size with reflective surfaces.

“I wanted it to be like a cosmetic counter at Bloomingdales,” Mr. Lee said. “Very well-lit and refreshed, where you get the feeling you’re going to look better when you leave.”

At 20 calories an ounce, customers are not likely to leave looking much worse for the wear, which is why the health-conscious treat has become a hit among fashionistas.

“I met Leonardo DiCaprio at dinner, and he knew more about the Pinkberry concept than even I did. He was talking about how he was sick of spending $50 a week on it,” Mr. Lee said with a laugh.

“It’s not about advertising, it’s about word of mouth, that’s how we were successful in Los Angeles,” Mr. Lee said, adding that Pinkberry’s staunchest detractors have been some of its best publicists. “So many people came to the location, the neighbors complained, then newspapers and TV covered the story and more people came.”

A spokesman for another purveyor of low-calorie frozen treats, Tasti D-Lite, issued a statement saying the chain does not consider Pinkberry “any competition at all.”

Pinkberry has opened stores on the Upper East Side and in Koreatown and Chelsea, and the next stop in its low calorie invasion of New York is Spring Street. Then it’s onto the other four boroughs and eventually to England, France, and Australia.

Although the expansion sounds terrifyingly rapid, Ms. Hwang, a USC business school graduate, says she has been careful in choosing locations “where people want to diet.”

Fresh out of business school, Ms. Hwang intended to open an English tea room. She rented a tiny space in West Hollywood and consulted Mr. Lee, an architect, to help her design it. The neighbors fought the project from the beginning. First, they voted down outdoor seating, then she was denied a liquor license to serve sherry. Now a couple, Mr. Lee and Ms. Hwang rethought their business plan.

Having moved to Los Angeles from Korea in 1992, Ms. Hwang missed the frozen yogurt craze of the 1980s. Fifteen years in Los Angeles, however, has taught her what Southern Californians want — food that keeps them healthy and thin. Mr. Lee, captivated by the taste of the soft serve gelatos, suggested that a nonfat, nonsugared frozen yogurt product would be the perfect concoction to satiate the svelte.

Since its opening in 2005, however, Pinkberry’s most ubiquitous topping is controversy. A handful of copycat chains opened in Los Angeles and John Bae, the owner of Kiwiberry, filed a police report claiming Mr. Lee had threatened him with “great bodily harm.”

Although he finds the competition troubling, Mr. Lee said it’s the press’s extensive chronicling of such disputes that’s most upsetting. Particularly hurtful, he said, was a recent New York Times article reporting that Mr. Bae had requested a restraining order against him.
“I can’t handle this at all,” Mr. Lee said in a phone call from his car, denying that he threatened Mr. Bae.