The attacks prompted Karina, a member of the group Aespa, to post a handwritten note “to convey my sincere apologies to the fans”.

“An idol’s persona is expected to be romantically available,” said Stephanie Choi, a K-pop expert with the University at Buffalo’s Asia Research Institute.

Especially for young women, who often start in the business as teenagers, there is a lot of “promotional emphasis on innocence and chastity”, and it is hard for them to move past this, Choi said.

Cost of fame: South Korean actor’s suicide sparks outrage over privacy invasion

Western stars such as Britney Spears and Miley Cyrus have also experienced blowback as they turn from girls to women in the public eye, but the business model of South Korean K-pop makes it particularly intense for local idols.

But in return, they may expect their idols to be held to “gruelling professional standards” which extend into their personal lives, with young female stars particularly vulnerable, Bae said.

“Purity and ‘girlishness’ have remained important images, and unfortunately this can really backfire on the idols when they are discovered to be dating, drinking and smoking,” she said.

In the early 2000s, before K-pop swept to world recognition, dating was essentially banned for aspiring South Korean pop stars.

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K-pop star Sulli found dead at home

K-pop star Sulli found dead at home

Park Joon-hyung, a member of popular K-pop band g.o.d, famously gave a tearful press conference in 2001 when he was asked to leave the group by his agency following reports he was in a relationship.

“If I’m guilty of one thing, it’s that I met someone I love,” he said. “I am 32, OK? I, Park Joon-hyung, am 32 years old and I have a girlfriend,” he added, tearing up.

Expectations have gradually relaxed, and many popular K-pop stars such as IU, SNSD’s Sooyoung, Jiyeon and BoA, have confirmed relationships to the press.

But being open about one’s relationship status is a privilege reserved for established stars, while newcomers in the competitive K-pop industry – like Karina – are discouraged from dating to avoid jeopardising their popularity.

“The idea of dating or the potential to date a K-pop star is definitely used as a business and marketing strategy,” Billboard’s K-pop columnist Jeff Benjamin said.

Part of what makes new idols marketable and profitable is allowing fans to entertain the notion that “maybe, one of the fans may date the idol themselves – as delusional of a thought as it may be,” he added.

Netizens slam K-pop singer for drinking Starbucks coffee: ‘educate yourself’

Many K-pop idols start training as teenagers, when they are typically banned from dating, and recently major celebrities have spoken about how lonely and repressive this method of minting stars can be.

“It’s really harsh,” megastar band Blackpink member Jennie said in a Netflix documentary.

“We were not allowed to drink, or smoke or get a tattoo,” she said of her training period, and had to endure “being told that I’m not good at stuff”.

Late star Sulli, who took her own life in 2019 at age 25, also spent around four years as a K-pop trainee, before making a debut as a member of popular girl group f (x) at age 15.

In a biographical documentary released posthumously last year, she revealed that when she turned 20, there were only two things she wanted to do: “to get counselling from a psychiatrist and to date.”

Her relationship with Choiza, a rapper 14 years her senior, which became public when she was 20, along with other moves away from her erstwhile idol image – like not wearing a bra in public – triggered relentless online bullying.

“When I started out in the entertainment business, there was one thing people wouldn’t stop telling me,” she said in the film.

“You are a product. You need to exist as the finest, top-quality product to the public.”