Only a handful of Korean acts have experienced that singular thrill. Despite K-pop’s strong physical sales, booming streaming numbers and titanic influence on social media (LOONA alone has 1.6 million Instagram followers), it has long struggled to gain traction on American radio, an institution that doesn’t play a lot of non-English pop songs. So Korean artists looking to break through on U.S. airwaves typically adapt to the market with strategic label partnerships, Western collaborations, and English-language singles — and LOONA has adopted the lattermost option with “Star.”

Before LOONA ever attempted to cross over, though, the group — whose members range in age from 18 to 24 — promoted each member individually before debuting as a 12-member unit under its Korean management company, BlockberryCreative. In an atypical move, the members of LOONA were announced over a two-year period: each month, a new face was revealed to the public — hence its Korean name, 이달의 소녀, which translates to “girl of the month” — along with a solo single. Throughout this ambitious pre-debut process, three official subunits were formed (1/3, ODD EYE CIRCLE, yyxy), and an elaborate fandom was created called the LOONAverse.

As Heejin, Hyunjin, Haseul, Yeojin, ViVi, Kim Lip, Jinsoul, Choerry, Yves, Chuu, Go Won, and Olivia Hye were introduced, the spectrum of LOONA’s sound only grew more diverse, from the saccharine bombast of Chuu’s “Heart Attack” to Kim Lip’s hazy R&B to the future bass intensity of JinSoul’s “Singing in the Rain” to the Grimes features on yyxy’s synth-heavy “love4eva.” Meanwhile, the anticipation for the full group to finally arrive grew more feverish.

“We were happy to be the main characters,” Chuu adds. “It took a long time to debut as a whole, but I’m proud that we’ve created our own unique characteristics.”

Looking back, Heejin, who joined the company as a trainee at 15, says she was initially worried about the unusual process. “At first, there were lots of concerns, wondering if this project will be able to gain attention from the public since it was something very new,” she says. “Now, I’m very proud of my [solo] album and the fact that [our projects] became what makes LOONA so special.”

The intensive launch strategy culminated in August 2018 with the release of LOONA’s first official single, the hyper and hooky “Hi High.” While the LOONAverse was a creative concept built with the group’s fans, Orbits, in mind, LOONA has done fairly little press in the U.S., aside from a 2019 performance at KCON LA. Without much name recognition in America beyond Twitter and no support from a major label — but a strong belief in the crossover potential of “Star” — BlockberryCreative doubled down on an expansive global strategy.

That plan started with the launch of a digital initiative last October called “Map of Orbits,” a website where LOONA’s fans could register to become a star in the group’s galaxy, with thousands of stars surrounding LOONA’s moon. From there, BlockberryCreative prioritized local promotion, investing in digital advertisements and a billboard in Los Angeles in support of LOONA’s third EP, [12:00] (pronounced “midnight”), which hit No. 112 on the Billboard 200 last October.

“Star,” included as a B-side on the EP, was recorded in English as a gift for LOONA’s international fans (the Korean-language version of the track is called “Voice”). And its music video, which arrived in November and has since earned over 10 million YouTube views, was the bow on top.

“Having a full English song was the best way we could get attention from the radio stations,” a representative from the group’s U.S. team says. “LOONA has no feature with a Western artist. It’s just LOONA.”

As such, the song had to appeal to mainstream audiences with a trendy retro sound that ushered in a change in LOONA’s sonic direction. Go Won was excited to show a “different side” of LOONA, while Olivia Hye thinks the message of togetherness is more important than ever: “You can understand and enjoy it easily because it’s meaningful without being too complicated,” she says. Adds Jong Hyeon Lee, CEO of BlockBerryCreative, “I want LOONA to become a group that overcomes cultural and language barriers globally.”

“Star” has climbed to No. 32 on Pop Airplay in its fifth week on the chart, garnering 3.5 million on-demand streams, according to MRC Data. It has also been the most requested song on iHeartRadio Most Requested Live for five consecutive weeks, with LOONA fans reaching out to individual stations and DJs around the country to request more spins.

“It just grew and grew, and we got lucky,” their U.S. rep says. “Now radio DJs and promoters are like, ‘Hey, we want to meet these girls.’ Because the fan engagement is crazy.”

A version of this article will appear in the March 13, 2021 issue of Billboard.