Maybe you saw them piled on the klieg-lit couches of Ellen DeGeneres and Jimmy Fallon, trading light bilingual banter with their starstruck hosts. Maybe it was when they spoke solemnly on mental health and self-love at the United Nations General Assembly last September, or when a wall of dolphin-like screams greeted them as they rolled into February’s Grammy Awards in trim matching tuxedos, their hair tinted various shades of pastel macaron.

Or maybe the cover of this magazine is the first time you’ve truly noticed BTS. (Stranger things have happened in 2019.) But it seems indisputable to say that sometime over the past two years, the septet have taken over the world: two No. 1 albums on the Billboard chart in the span of three months; more than 5 billion streams combined on Apple Music and Spotify; a string of sold-out concert dates from the Staples Center in Los Angeles to London’s famed Wembley Stadium.

Image zoom Peter Yang for EW

That hardly makes them the first boy band to dominate a cultural moment, but the fact that they are all Korean-born and -raised, singing Korean-language songs only occasionally sprinkled with English, feels like something brand-new. And it speaks to an unprecedented kind of global currency — one where pop music moves without barriers or borders, even as geopolitics seem to retreat further behind hard lines and high walls.

On a blindingly bright March day in Seoul five weeks before the release of their upcoming sixth EP, Map of the Soul: Persona, the band is holed up at their record label Big Hit Entertainment, preparing. Buildings like this are where much of the magic of the phenomenon known as K-pop happens, though Big Hit’s headquarters on a quiet side street in the city’s Gangnam district (yes, the same one Psy sang about in his 2012 smash “Gangnam Style”) look a lot like any other tech office: sleek poured-cement corridors and glass-box conference rooms scattered with well-stocked mini-fridges, plush toys, and the occasional beanbag chair. Only a display case stacked with a truly staggering number of sales plaques and statuettes, and a glossy large-scale photo print of BTS at their sold-out concert at New York’s Citi Field last October, give away the business they do here.

Down a long hallway, all seven members lounge in various states of readiness as they gear up to pretape a thank-you video for an iHeartRadio award they won’t be able to accept in person. Jimin, bleached blond and pillow-lipped, is having his hair carefully flat-ironed in a wardrobe room filled with racks of coordinated denim and neon streetwear. Dozens of pairs of pristine Nikes and Converse are piled in a corner; a lone fun-fur jacket the color of strawberry ice cream slumps on a hanger behind him, like a neglected Fraggle.

Jung Kook, the baby of the band at 21, sits obediently in a folding chair in the dance studio, also having his hair tended to; J-Hope strides by in a white dress shirt emblazoned with an over-size silk-screen of Bart Simpson, then grins and disappears. Suga, V, and Jin huddle together on low sofas next door, scrolling through their phones and occasionally singing fragments of American R&B star Khalid’s “My Bad.” Twenty-four-year-old RM, the group’s de facto leader and lone fluent English speaker, is the last to arrive.

They run through their speech for a camera crew and do maybe four or five takes until the director is satisfied. Then they settle in for a conversation in an airy break room upstairs, accompanied by their longtime translator, a large, amiable bald man in a business suit named John. (Unless noted, the answers of all members other than RM come through him.) Several weeks after returning from their first Grammys, they’re still riding high off the experience: presenting the award to H.E.R. for Best R&B Album; chatting with Shawn Mendes in the men’s room — “I was like, ‘Do I need to tell him who I am?’ ” Jimin remembers, “but then he said hello first, which was really nice” — and being seated only a sequin’s throw from Dolly Parton. (“She was right there in front of us!” marvels Jung Kook. “Amazing.”)

As happily dazzled as they still seem to be by other celebrities, seeing BTS in the flesh triggers the same disorienting but not unpleasant sense of unreality. On screen, the band can look disconcertingly pretty; avatars of a sort of poreless, almost postgender beauty who seem to exist inside their own real-life Snapchat filters. In person they’re still ridiculously good-looking, but in a much more relatable, boyish way: bangs mussed, even the occasional chapped lip or small (okay, minuscule) blemish. Take away their Balenciaga high-tops and the discreet double Cs of Chanel jewelry, and they could almost be the cute college guy next to you at the coffee shop or on the train.

Image zoom Peter Yang for EW (2)

Except riding public transportation or casually dropping into a Starbucks stopped being an option for BTS a long time ago. In Seoul, their faces are plastered across makeup kiosks and street signs and the sides of buses — even on massive digital billboards that are bought and paid for by private citizens to acknowledge a beloved member’s birthday, or just because. In cities like São Paulo and Tokyo and Paris, fans camp out days in advance for concerts and public appearances, obsessively trading trivia and rumored sightings. When the band posted their take on Drake’s #InMyFeelingsChallenge, it became the most liked tweet of 2018; this summer, Mattel will release an official line of BTS dolls.

In the still center of this bizarre fame hurricane, the boys have managed to find a few pockets of normalcy. Jimin wistfully recalls a time in Chicago when they were able to slip out of their hotel rooms undetected “late at night, just to get some fresh air.” But most places, he admits, “that’s really out of the question” unless they split into smaller groups. “I mean, look at us,” RM adds with a laugh, running a hand through his own silver-nickel bangs. “Seven boys with dyed hair! It’s really too much.”

Instead, they focus on the things they can do, like sneaking out to the movies (“Always the latest or earliest show,” says RM, if they want to stay unseen), shopping online (V loves eBay, especially for clothes), going fishing, playing StarCraft at home. Group housing is actually common for K-pop stars, and BTS seem to appreciate the shared stability: “We’ve been living together for a while now, almost eight, nine years,” says Jimin. “So in the beginning we had a lot of arguments and conflicts. But we’ve reached the point where we can communicate wordlessly, basically just by watching each other and reading the expressions.”

Image zoom

Though they’re unfailingly polite and attentive in interviews, there’s a certain amount of contained chaos when they’re all together — a sort of tumbling-puppy cyclone of playful shoves, back slaps, and complicated handshakes — but also a surprising, endearing sweetness to the way they treat one another in quieter moments. When a question is posed to the group, they work hard to make sure each one of them is heard, and if someone is struggling to find a word, they’ll quickly reach out for a reassuring knee pat or side hug.

Even with the language barrier of speaking to an American reporter, though, their individual personalities quickly start to emerge: Asked to name their earliest pop memories, the answers land all over the map. “I loved Pussycat Dolls’ ‘Stickwitu,’ ’’ says J-Hope, the group’s most accomplished dancer, snapping his fingers and cooing the chorus. For RM, who started out in Seoul’s underground rap scene, it’s Eminem’s “Lose Yourself.” (“I think that’s, like, a life pick for so many people around the world,” he admits, “but I can’t forget when I first watched 8 Mile and heard the guitars. That was my turning point.”) For Jung Kook, who has released covers of Justin Bieber and Troye Sivan songs, it was Richard Marx’s deathless lite-FM ballad “Now and Forever.”

The soft-spoken Suga cites John Lennon’s “Imagine” as “the first song I fell in love with,” which feels like a fitting gateway to ask where BTS see themselves in the pantheon of musical heartthrobs that the Fab Four essentially invented. “Sometimes it feels really embarrassing when someone calls us a 21st-century Beatles or something like that,” RM concedes. “But if they want to call us a boy band, then we’re a boy band. If they want to call us a boy group, we’re a boy group. If they want to call us K-pop, then we’re cool with K-pop.”

Ah, K-pop. In South Korea, where the genre has become not just a prime cultural commodity but a multibillion-dollar export, the players, known as “idols,” go through rigorous Fame-style schooling in song and dance and media training that often goes on for years before they’re considered ready for the spotlight. And it’s paid off: Business has been booming since the early ’90s, with stars from Girls’ Generation to G-Dragon crossing over to various markets across Asia, Europe, and the Americas. But while the sound has remained fairly consistent — a canny mix of club-ready beats, hyper-sweetened choruses, and the more urban inflections of Western hip-hop and R&B — it’s never before landed with the lightning-bolt impact of BTS.

Image zoom Peter Yang for EW

Bang Si-Hyuk, the CEO and founder of Big Hit, began putting the band together in 2010, when all the members were in their tweens or teens: RM and Suga were coming up on the local rap scene; Jimin and J-Hope studied dance at performing-arts schools; V, who focused on singing early on, joined officially in 2013. Jin was an aspiring actor recruited off the street for his striking looks; Jung Kook, now the group’s main vocalist, joined while he was still in junior high.

Though fansites tend to lean on their extracurricular differences (Jung Kook is a Virgo who loves pizza! V collects ties and clenches his teeth in his sleep!), each member genuinely does hold a unique space in the group’s process, whether it’s leaning more toward production, lyrics, or the supersize hooks the songs rest on. “With seven members we have seven different tastes, of course,” says RM. “So when it comes to songwriting, it’s like a big competition.” Occasionally, adds J-Hope, “we’ll write a lyric and decide, ‘This sort of reflects me [more], who I am and my own color,’ so we’ll want to keep that for a solo song.”

Because Big Hit doesn’t restrict their right to funnel some ideas into side projects — and because the appetite for more BTS-sourced material online is seemingly unquenchable — members regularly release solo work through EPs, SoundCloud, and mixtapes. But the primary impact still comes through the official album releases, and the particularly weighty subjects those songs take on — a notable departure from the narrow, often strenuously upbeat topics other K-pop artists typically cover.

“I promised the members from the very beginning that BTS’ music must come from their own stories,” says Bang; their subsequent openness about their own struggles with depression, self-doubt, and the pressure to conform took them all the way to the U.N. last fall, where RM addressed the band’s Love Myself campaign and #ENDviolence youth partnership with UNICEF.

Image zoom Peter Yang for EW (2)

“They stand out,” says Japanese-American DJ and producer Steve Aoki, a top-selling global dance artist who has also collaborated with the band on several tracks. “And I’m not just talking about K-pop. They add so much of their personality to the music and into their stories and how they present themselves. And the world has fallen in love with them because they are showing that vulnerable side that everyone wants to see.”

It helps, too, that the group’s more pointed messages are often slipped into the sticky aural peanut butter of anthems like “No More Dream,” “Dope,” and “Am I Wrong.” But they always appreciate the chance, Suga says, to get “a little more raw, a little more open.” RM elaborates: “I think it’s an endless dilemma for every artist, how much we should be frank and honest. But we try to reveal ourselves as much as we can.”

Honesty has its limits, of course, when you’re the biggest band in the world. Asked to describe the new album, due April 12 (at press time, it had already hit over 2.5 million in preorders), members offer up cryptic but enthusiastic koans like “therapeutic” and “refreshing crispness.” To be fair, they can’t say much in part because the new album’s track list isn’t actually finalized yet — late decisions being a luxury of in-house production — though they do agree to play one song, a propulsive rap-heavy banger called “Intro: Persona.” (It was released as a teaser March 27; you can watch the video here.)

When it comes to more personal questions about the challenges of dating or the goals they might want to pursue post-BTS, they pivot so gracefully to evasive, nonspecific answers, you almost can’t help but be impressed; it’s like watching a diplomat ice-dance. They want you to know that they are incredibly grateful for the devotion of their fans, and so blessed to be exactly where they are; that they really don’t think in terms of five- or 10-year plans. But they turn reflective when the subject of American pop’s holy grail, the Hot 100 singles chart, is raised. They cracked the top 10 last year with “Fake Love” but have yet to reach a higher spot, largely because mainstream radio airplay—a huge component of Hot 100 domination—still eludes them Stateside.

“It will have to be a great song,” Suga acknowledges, “but also there’s a whole strategy that’s associated with getting all the way up. And then there has to be a measure of luck, obviously. So what’s important for us is just to make good music and good performances and have those elements come together.” Does a Spanish-language smash like 2017’s “Despacito” — which spent a record 16 weeks at No. 1 — make them more optimistic about their own odds? “You know, Latin pop has its own Grammys in America, and it’s quite different,” RM says thoughtfully. “I don’t want to compare, but I think it’s even harder as an Asian group. A Hot 100 and a Grammy nomination, these are our goals. But they’re just goals — we don’t want to change our identity or our genuineness to get the number one. Like if we sing suddenly in full English, and change all these other things, then that’s not BTS. We’ll do everything, we’ll try. But if we couldn’t get number one or number five, that’s okay.”

Image zoom Peter Yang for EW (2)

Aoki, for one, has faith they’ll get there. “I think it’s 100 percent possible that a song sung entirely in Korean could crack the top of the Hot 100. I firmly believe that, and I really firmly believe that BTS can be the group that can do that. It’s going to pave the way for a lot of other groups, which they’ve already been doing—and when that happens, we’re all gonna celebrate.”

Back at Big Hit, though, the band has more immediate work to do. RM offers a quick tour of his production room (each member has his own dedicated space on site). The door outside is guarded by a quirky assemblage of figurines by the renowned street artist Kaws, but inside feels, incongruously, like stepping into a tiny, luxurious Sundance lodge that also just happens to have a soundboard: There’s a beautiful coffee table made from a single piece of black walnut; Navajo-style rugs; tasteful art on the walls. RM talks easily about his admiration for producers like Zedd and the Neptunes (“Pharrell Williams and Chad Hugo were my true idols in 2006, 2007. Pharrell’s voice! It’s so sexy, how he sings”), and plays down his own skills (“As a beatmaker, Suga is way better than me. I don’t even know how to play the piano — I just do the chords like this,” he insists, miming keyboard Muppet hands).

Then it’s back to the dance studio, where they’ve changed into track pants and T-shirts to run through new steps with a choreographer. It starts with a rough triangle formation, and an elaborate hip-swivel-into-pelvic-thrust/crotch-grab combo that actually plays much more innocently than it sounds, mostly because they keep stopping to crack each other up. Soon, though, they drill down — repeating the moves until they seem crisp but easy, almost an afterthought. It feels like time to leave them; the boys wave happily, shouting out a rowdy chorus of goodbyes. Then they turn back to the mirror, and keep dancing.