BLACKPINK has the bad girl image down to a tee. The K-pop girl group’s music video for “DDU-DU DDU-DU” has the kind of set pieces of an overwhelmingly anthemic fever dream. Each of the four members has their own instantly memorable scene. There’s fierce and luxurious Jennie who relaxes on a tank. The bubbly and affable Lisa goes all-in on camp as a high-fashion professor wielding a recognizable pink hammer. The quirky Jisoo trips over her platform heels on a red carpet (because relatability). Then resident songstress Rosé appears like a goddess on a chandelier swing.

It’s a decadent, outlandish, stylish visual that accompanies lyrical braggadocio like, “In my hands is a fat check/ If you’re curious, do a fact check.” And the song did outdo their previous high-performing singles: “DDU-DU DDU-DU” became BLACKPINK's first Billboard Hot 100 entry at No. 55, while the music video went on to become one of the most-viewed in 24 hours of all time. No wonder why they are K-pop's most visible representatives of the concept known as “girl crush” in 2018.

Defining K-pop’s version of “girl crush” presents a logistical challenge because it has such a dynamic meaning. The term could refer to a group’s overarching concept (think girl group powerhouse 2NE1), a more ephemeral song concept (like Girls’ Generation’s sassy kiss-off “You Think”) or even an individual girl group member (TWICE’s short-haired Jeongyeon). There isn’t really a specific sound to “girl crush” -- it functions more as a descriptor of both visuals and message, to varying degrees. (As with the Western counterpart of the term, the romantic implications of the word “crush” tend to be overlooked, veering into the “gal pals” variety of LGBTQ erasure.)

Still, a song will hardly qualify for the label if it sounds too cute and bubblegum. The concept goes harder as idols morph into badass, tomboyish and occasionally sexy women. But it often boils down to “you know it when you see it.”

There are the usual sartorial signifiers: sports jerseys, fishnets, menswear, Doc Martens and dark color schemes. Basically, anything that conveys the image of ferocity, stepping outside the expectations of hyperfemininity. But, ultimately, “girl crush” concepts amount to more abstract ideas of relatability, aspiration and female empowerment.

It’s hard to say when the exact concept of girl crush arrived in Korea, but precedents can be traced back to the 1990s, with pop singer Lee Sang-eun (also known as Lee Tzsche). “She’s really a tomboy,” says Dr. Suk-Young Kim, author of K-pop Live: Fans, Idols, and Multimedia Performance and professor at University of California, Los Angeles. “I thought it was really curious because we’d never seen anything like that before. Teen pop stars in the ‘90s before [K-pop originators] Seo Taiji and Boys came along, they were all IU types — these soft-spoken girls with a pretty face. And she was so different.”

The concept became much more developed by second-generation acts (who debuted between the mid-2000s to early 2010s) -- particularly 2NE1, 4Minute, miss A, Brown Eyed Girls and f(x). Although all five groups have wildly different discographies, they each managed to package an aspirational version of womanhood that was both individualistic and fashion-forward.

2NE1’s 2011 hit “I Am the Best” is one of the most iconic girl crush concepts on many levels. It’s a boastful banger directed at women with attitude to spare. The abrasive styling choices -- baseball bats! studded leather jackets! gravity-defying haircuts! -- are emblematic of 2NE1’s cartoonish fashion, which often bucked the male gaze. The quartet even acknowledges their appeal to female fans in the lyrics as Bom sings, “Girls are following me.”

Fast-forward to 2018, and there was no shortage of girl crushes in K-pop. The concept always makes an appearance in a handful of songs every year -- but this year saw over 20 acts transform into fierce divas. (G)I-DLE have been, well, crushing it as the latest monster rookies with their hard-hitting debut “LATATA.” Mamamoo, CLC and Girls’ Generation subunit Oh!GG returned to the concept. More versatile groups like gugudan, Pristin V and Red Velvet tried it on for the first time.

But beyond the usual suspects, some fans were shocked to find more unexpected girl groups go girl crush. Fans tend to think of Apink, Oh My Girl and April as cute incarnate. But in 2018, those artists put their innocent images on the backburner (to a certain extent) to do some mean-mugging. Even aegyo-shilling TWICE returned to a softer version of a girl crush single for the first time since their 2015 debut, where they partied with zombies in “Like Ooh-Ahh.”

You might wonder, “So what?” All of the women in American pop are buoyed by huge female followings. Why is K-pop any different? But the (heteronormative) gender breakdowns of K-pop fandom are traditionally much more divided. The boy groups usually snag the majority of the female fan base, while girl groups followings tend to skew male. That gender split gives boy groups an edge when it comes to longevity.

“Boy group fandom looks very homogenous when compared to girl groups, because boy bands thrive on this number of dedicated, heterosexual girl fans,” says Dr. Kim. “[Female fans] just tend to understand from the get-go that their idols’ future totally depends on how they patronize them.” Girl groups, on the other hand, have to appeal more broadly to the general public. To chart out new fanbases, Dr. Kim says, they “try on all kinds of concepts, from sexy to cute and innocent.”

Of course, all-male groups regularly shapeshift between concepts too. But Aja Romano, an expert on fandom culture who writes for Vox, observes that girl groups switch concepts at a more accelerated rate. “The girls are more likely to undergo total transformative overhauls from video to video more than the boys are,” she says. “That’s been the biggest difference to me between the boys and the girls. I always feel like I’m watching BIGBANG do a BIGBANG video.”

Red Velvet is the standard-bearer for girl groups’ conceptual versatility. They got down to brash tracks this year with “Bad Boy” and “RBB.” But they broke up these darker visuals with the sweet and bubbly “Power Up.” This instantaneous flip between cute and dark could be jarring for most groups, but the quintet has mastered the art of conceptual transformation. After all, the split between their livelier red and mature velvet sides was part of the group’s concept since its debut.

According to this year’s K-pop Reddit Census, Red Velvet was the overall favorite group among every gender and sexual identity on the r/kpop subreddit. The five-member girl group is known for their ability to appeal to a co-ed fandom, and they recently had their biggest U.S. album sales week. When asked about the group’s large female following, resident girl crush member Seulgi acknowledged her position as a role model: “It’s so flattering to have people who want to be more like you,” she told Hypebae. “It makes me want to work harder to be a good influence and also inspire our female fans in that way.”

SM Entertainment appears to be blasting the typical girl group business model. According to Seoulbeats, the unwritten “rule of one” states that a company can only promote one girl group at a time because they make the bulk of their money through advertisement deals, called “CFs” or commercial films. In contrast, boy bands rely on music promotions and merchandise -- which becomes a steady stream of income if you have a loyal (read: female) fandom. More than one girl group means competition for limited ad placements, so female idols often leave their company after their contract expires.

SM, on the other hand, promotes both Girls' Generation and Red Velvet, along with f(x) members and veteran soloist BoA. Red Velvet’s music promotions are presumably profitable enough given that the quintet will soon embark on a five-city theater tour through the U.S., which is a rarity for girl groups.

The company’s Visual & Art Director Min Hee Jin reportedly spoke about SM’s fandom strategy on SBS Korea’s The Unanswered: "Our main target isn't men in their teens, twenties, or thirties. The male fanbase will follow no matter what happens. Overall, our main target is women in their teens and twenties. In order to gain their interest, we give [our girl groups] a confident and modern image."

The spending power wielded by female fandom is not exclusive to K-pop. It’s just that the South Korean music industry seems more open to recognizing women as a market force (which is probably the most genuine element of female empowerment to “girl crush” concepts). “We know just in general that women are more prone to spend money on pop culture than men are,” says Romano. “Women have the spending dollars and the drive to actually shell out money for their favorites.”

The key demographic of 18-to-34-year-old men has long been considered the end-all-be-all when it comes to targeted advertising. “The idea is that if you can appeal to this certain subset of men, then you somehow reach as far as you can reach into the culture,” Romano says. But NPR, Marketplace and AdWeek reported earlier this year that this male-centric sweet spot was on the decline -- which leaves room for different groups to influence the market.

While female fandom is often written off as shallow, even Western pop culture is slowly embracing the value of women as consumers. “There’s an element that we see throughout all of culture where male purchasing power is valued more,” Romano says. “We’re in a moment where all across the world, pop culture and media producers are going, ‘Wait, why don’t we give girls things that girls like and let them spend money on things that they like?’”

This year’s uptick in girl crush concepts is happening during a peculiar political moment in Korea. The #MeToo movement spread throughout the country earlier this year, toppling notable figures accused of sexual assault. Gender relations have become more tense in the past few years as women demand equality in a society that still has, for example, one of the worst gender pay gaps.

But fans generally understand girl crush to be a heavily constructed concept that, for the most part, doesn’t convey a substantive image of female empowerment. “There’s no middle ground between the broader social change that’s happening in the global movement and this K-pop parade that’s really a marketing strategy,” Dr. Kim says. “K-pop idols are like British royalty. They can’t say anything political. Otherwise, it’s too risky.” (To be fair, the pop culture embrace of marketplace feminism is hardly unique to K-pop.)

The label “feminism” is too taboo for the apolitical K-pop industry to outwardly embrace. The faintest hints of "girl power" have dire consequences for female idols. Apink’s Naeun was flamed online for posting a picture on Instagram where she held a phone case that said, “Girls can do anything.” Similarly, Red Velvet’s Irene got backlash from her male fans for reading Cho Nam-joo's feminist novel Kim Ji Young Born 1982. There were reports that some fans even burned her picture.

Granted, there are female idols who’ve been vocal about taking ownership of their femininity. Girls’ Generation’s Sooyoung opened up about everyday inequalities on her reality show, Born 1990, Choi Sooyoung, which was named after the same novel. Former Sistar member Hyolyn is serving up sexy concepts while calling the shots at her own company, Brid?. Top soloist and former 4Minute member HyunA co-wrote and styled former labelmate CLC’s girl crush anthem, “Hobgoblin.” Her brand of in-your-face sexuality gets mixed reactions, but she appears to be wresting control of her image. When Cube Entertainment denied her dating rumors, she later confirmed that she was dating Pentagon’s E’Dawn -- which led to Cube firing both idols earlier this year.

“Overall, themes [in K-pop] regarding female empowerment or anything that sounds feminist have [disappeared], perhaps because of the vigorous feminist movements in Korea these days,” says Stephanie Choi, a doctoral candidate in ethnomusicology at University of California, Santa Barbara. “I think the industry is trying to move away from anything that seems feminist."

Most “girl crush” songs wouldn’t pass the Bechdel test. Not that they necessarily need to -- love songs directed at a male love interest can just as easily be a point of aspiration for a (straight) female fan. But any hints at girl power generally stop at the visuals.

There were a few songs this year that stood out as “girl crush” in terms of empowering lyrics, particularly BoA’s “Woman.” The first-generation K-pop singer wrote the lyrics, which focus on self-empowerment through inner beauty. "The word 'woman' is a sensitive subject, but personally I think humankind is able to exist because men and women are equal," she said in a press showcase, according to Yonhap News. "I wanted to write a song that raises women's self-esteem.”

But first-generation idols can get away with more than third-generation idols. “BoA is also somewhat ‘safe’ in terms of her status and relationship with her fans,” Choi says over email. “She's one of the first-generation idols who have been freely using feminist themes (like Lee Hyori), and during that time fans didn't have much voice and control over the music industry production. But I think if Red Velvet makes the same [empowering] production that Lee Hyori and BoA made back then, they would have a huge backlash.”

On a lyrical level, girl power anthems used to be more common. During 2NE1’s reign, CL became one of the most visible figures of women's empowerment in K-pop, appointing herself the "Baddest Female" in 2013. The song is emblematic of her stage presence: brash, unapologetic and energetic. The ultimate girl crush jam celebrated sisterhood with its “where all my bad girls at” hook. CL even linked up with fellow bad girl Lee Hyori for a special stage. The song birthed her solo fandom name: GZB, reclaiming the Korean word “gijibae,” which is a derogatory term for a bad girl.

It’s hard to quantify just how successful the girl crush theory is when it comes to developing a strong female fanbase with longevity. (Obviously, women have diverging concept and music preferences.) The major girl crush groups of the secon generation like 2NE1, 4Minute and Brown Eyed Girls all performed pretty consistently toward the top of the charts before hiatus or disbandment. CL even had a minor hit in the States, as “Lifted” hit No. 94 on the Hot 100 in 2016.

Aside from (G)I-DLE’s monster rookie debut, the concept doesn’t seem to have significantly changed any group’s performance on Korea’s Gaon charts in 2018. However, the girl crush concept does appear to correlate with a higher success rate on Billboard’s World Digital Song Sales chart -- CLC’s two entries on the Billboard charts, “Hobgoblin” and “Black Dress,” also happen to be their only girl crush singles. At the same time, several girl groups’ use of the concept didn’t appear on the Billboard charts this year.

The biggest exception this year is TWICE, whose cute concepts fare better on both Korean and American charts than their girl crush counterparts, “Yes or Yes” and “Like Ooh-Ahh.” All of their songs do quite well, so they don’t have too much of a conceptual gulf on the charts. But the saccharine “Likey” from 2017 is their only No. 1 on Billboard’s World Digital Song Sales chart. (In related news: a 2017 survey by Korean company LINE showed that TWICE’s Japanese fandom skews female at 66 percent versus 34 percent male fans.)

The takeaway is that girl crush appeals more widely to a Western palate that might not be used to cute and innocent concepts. Not to mention, the U.S. market has long been more amenable to female empowerment anthems in general. From that point of view, the omnipresence of girl crush in 2018 overlaps with the fact that K-pop is more relevant in America than ever before.

Last year rocked the K-pop world, as mass disbandments of second-generation girl groups like Wonder Girls, miss A and Sistar took place. It was the clearest sign that even the most established girl groups struggle with longevity. “A lot of the girl groups who are still around from the second wave, they’re succeeding off the backs of the girl crush idea that’s gotten more and more evolved over time,” Romano says. Girl crush veterans Brown Eyed Girls and f(x) are technically still together -- but neither has released full-group music since 2015.

In essence, girl crush is just a play at changing the typical gender dynamics of fan-idol connection. The concept seems to be working well for BLACKPINK, (G)I-DLE and even Red Velvet. But TWICE’s runaway success also proves that aegyo-level cute concepts can get the general public on your side. So girl crush can potentially put a stopper to the new generation’s expiration dates, while there’s still room for more commercially viable versatility.

“I don't think girl groups must have a girl crush concept to appeal to female audiences,” says Choi. “Girl crush concepts can be one of the ways that attracts female fans, but … the artists' communication and fan service skills really builds sisterhood between the artists and fans.”