Editor’s Note: A fresh episode of “The Whole Story: K-Pop: A Star is Made,” showcasing the journey of teenage girls striving to become idols, airs Sunday, January 5th, at 8 p.m. ET on CNN.

Inside a quiet room, seven teenage girls sit, anxiously awaiting their turn. Each of them is youthful, slender, and impeccably groomed, with ages spanning from 14 to 20. Their glossy hair and radiant skin are striking, but it’s their nervous expressions that set the tone. They’re moments away from discovering who among them will secure a spot in South Korea’s latest K-pop group – a shared dream for countless aspirants in Korea and increasingly around the globe as the genre’s popularity continues its meteoric rise.

The path to this pivotal moment has been anything but smooth. These young women have endured months, even years, of intense training in areas like singing, dancing, and rapping, all while adhering to strict fitness and diet routines.

Some have sacrificed their education, while others have left families far behind. In a fast-paced industry where youth is prized and groups often disband within a few years, the stakes have never been higher. Many believe this is their one and only shot.

“At 18, I’m considered old in this world,” shared Ah-In Lee, one of the final seven trainees from the K-pop company MZMC. “If I miss this chance, I fear no other agency would take me.”

CNN’s Kyung Lah gained exclusive access to MZMC during the critical final week of preparation before the agency’s first-ever group debut, documented in “The Whole Story With Anderson Cooper.”

Paul Thompson, MZMC’s founder and CEO, is an American songwriter and producer responsible for hundreds of K-pop hits. He revealed that the agency sifted through thousands of auditions to select about 30 official trainees, of which only seven remain after periodic eliminations.

These monthly assessments, routine across the industry, judge how quickly trainees are improving. Those who fail to meet expectations either drop out or are cut. This system highlights the rigorous nature of K-pop’s “idol training” model, which stands apart globally due to its comprehensive development programs. Agencies craft stars from the ground up, managing everything from training and debut schedules to public images, concerts, and even portions of their personal lives.

“The U.S. had something similar with Motown in the 1960s,” Thompson explained. “But it faded because it became too costly.” Yet, in South Korea, this method thrives. And compared to larger competitors, MZMC is relatively small; Thompson noted that larger agencies might take on hundreds of trainees before narrowing the roster to a final few.

Among MZMC’s trainees is Brittney Jang, a 20-year-old who grew up in the U.S. but returned to her native South Korea to chase her K-pop ambitions. Confident in her chances of being selected for the group, she also recognizes the weight of the moment. “If I don’t get chosen,” she told CNN, “then I can’t become an idol. This is my last opportunity.”

Intense Training and Constant Pressure

Each day for the MZMC trainees begins with two hours at the gym, followed by a marathon schedule of vocal and dance classes. The youngest members, like 14-year-old Liwon Kim, attend half a day of school before diving straight into practice sessions that often stretch past midnight.

Some trainees live apart from their families, such as 17-year-old Rana Koga from Japan, the sole non-Korean among the group, who resides in dormitories. The demands go beyond honing musical talent – the scrutiny on their appearance is unrelenting. South Korea’s beauty standards, which prize fair skin, slim figures, and delicate features, also influence the world of K-pop. Procedures like double-eyelid surgery are so common they’re often gifted to teenagers upon graduating from high school.

The expectations placed on K-pop idols are even more stringent. “They’re called idols for a reason,” said Thompson. “Fans don’t want stars who remind them of themselves. They look up to people who seem flawless and aspirational.”

The pressure to maintain a certain physique can take a dark turn. Amber Liu, a Taiwanese-American former idol turned independent artist, admitted that the intense focus on weight led her to harmful habits. “At 16, I didn’t know any better and just starved myself,” she said.

Min, a former member of the K-pop group Miss A, told CNN that female idols are often expected to weigh no more than 100 pounds (approximately 45 kilograms). This expectation deeply influences the routines of MZMC trainees, who carefully monitor calories and nutrients daily. “I try to calculate everything I eat, which is challenging,” said Lee, laughingly confessing her love for pizza. But she acknowledged, “Appearance is critical for idols since this is a job heavily centered on visuals.”

Thompson defended the training program, explaining that trainees’ body mass indexes (BMIs) are measured bi-monthly, while their diets include foods like roasted chicken and boiled eggs. “They’re eating enough,” he insisted, noting that maintaining the group’s cohesive look is essential. He also clarified that MZMC doesn’t push for plastic surgery, emphasizing that musical talent takes precedence in selection.

Still, the idea of surgery lingers in some trainees’ minds. Sixteen-year-old Seoyoung Yun, known for her lively personality and sleek black bangs, admitted she has considered procedures to refine her eyes. Though her father objects, Yun remains torn. “If it makes the public love me more, it might be worth it,” she mused. Ultimately, she concluded, “As long as it doesn’t stray far from my natural look, I believe it’s okay if it leads to success.”

The Cost of Stardom

Even after a group’s final lineup is set and they make their public debut, the pressures only intensify. With so many groups competing in a saturated market, Woonghee Kim, MZMC’s casting director, estimated less than 1% achieve the fame of globally recognized acts like BTS or Blackpink.

Those that do must deal with the burdens of superstardom. Staunch fans dissect every detail of idols’ lives, from performances to personal behaviors. Deviations, such as drinking or smoking, can provoke backlash severe enough to jeopardize careers. Dating is an equally fraught topic; fans have historically lashed out when idols reveal relationships. Last year, Karina from Aespa publicly apologized for her romance with an actor after fans threatened boycotts, and the relationship dissolved shortly after.

Experts have pointed out that K-pop’s industry is deeply intertwined with its fanbase, known for its dedication – from organizing charitable acts to paying for promotional campaigns. But the same devotion creates constraints, holding artists and agencies hostage to fan expectations.

“We teach the girls to be cautious,” Thompson remarked. “If they choose to pursue relationships or certain lifestyles later, they’ll need to do so privately.”

In recent years, some agencies have loosened their rules, mindful of the toll these pressures can take on idols’ mental health. Yun herself experienced a panic attack in 2023 after enduring years of monthly eliminations but was granted months off to recover.

Despite the challenges, the global allure of K-pop continues to attract aspiring stars. Following milestones like Psy’s viral hit “Gangnam Style” and the international success of groups like Blackpink and BTS, South Korea’s influence on global pop culture – from K-dramas to K-beauty – continues to grow.

For the seven MZMC trainees, the chance to be part of this world-changing phenomenon boiled down to a single moment. Behind closed doors, the MZMC team made their final choice. One by one, the girls were called in, their reactions ranging from elation to heartbreak. The result was the creation of a new group called VVS, named after a rare diamond quality. The group is expected to debut in early 2025.

The final members included Lee, Koga, Jang, Kim, and Jiu Moon. However, the atmosphere was bittersweet as two hopefuls, including Yun, didn’t make the cut. Yun has since pivoted to pursue a solo rap career. But K-pop is a competitive industry, leaving the future of these young women uncertain.

“We’ll find our audience,” Thompson expressed with confidence. “VVS will succeed, but whether it reaches Blackpink’s heights remains to be seen.”

This article has been updated.