In the West, pop’s reigning groups have, for decades, consisted of all-boy or -girl members, and in the frenetic K-Pop industry, you’ll find a similar situation. Co-ed groups, as they’re known in South Korea, aren’t just a rarity—they also struggle to attain the success experienced by their non-mixed contemporaries.

Consisting of two boys (rappers J.Seph and BM) and two girls (singers Somin and Jiwoo), K.A.R.D, a name that comes from each member represented by a playing card, are taking everyone by surprise and breaking through the barriers. Not only has their trilogy of pre-debut singles racked up more than 67 million views on YouTube alone since last December, but their success has happened outside South Korea, with a substantial, and seemingly overnight, international fan base appearance that’s allowed them to tour Brazil, Mexico, Canada, and North America before most rookie Korean groups even had their first solo concert on home turf.

While K.A.R.D are not immune to K-Pop’s ongoing tropical house trend, they’ve sought to mix things up by infusing their four singles to date with Latin and Jamaican influences, a sound which J.Seph describes as “reflecting the mambo genre, with a hint of dancehall and groovy beats.” The knife-edge choreography K-Pop is renowned for has also been reconsidered, replaced with still synced but more free-flowing routines. It might be a creative decision, but, says BM from Seoul where they’re promoting their official debut single “Hola Hola,” it’s a necessity “because we all have very different heights and bodies, so we try to show our own unique styles in the choreography.”

The four members, who return for second U.S. tour in September, are currently facing a new challenge: to gain more recognition in South Korea. The notoriously draining K-Pop promotional gamut runs from late-night radio shows to the televised weekly chart music shows where groups perform in front of small but fever-pitch audiences, and it’s been, admits J.Seph, “hard getting used to, but I think we’re starting to get the feel of it.” This tight schedule is why it’s nearing midnight in Korea when we can catch up with K.A.R.D to talk about success, secrets, K-Pop training, and dinosaurs.

Congratulations on your official debut! Now that the EP Hola, Hola and its title single are finally out, how are you feeling about this milestone moment? BM: It’s very hectic, but it feels good to finally debut.Jiwoo: It’s crazy. I’m so happy, but I still can’t believe what’s going on right now. Everything is still so new. Actually, ever since “Oh Na Na,” everything seems really cloudy, it’s so surreal.

K.A.R.D's project songs were quite dark, especially “Don’t Recall,” which was about a disintegrated relationship, but “Hola Hola” is a big contrast, very summery and fresh. Does this change signal a new look overall?Somin: I think “Hola Hola” really pushed the theme of a new start, as well as the feeling of summer.BM: It also had to do with the season that we made the music in. Our first song [was released] in December, so even though the music is bright, we wanted to match the season [visually].

Does that mean the next single will be a continuation of “Hola Hola”s style?BM: Hmmm, I think we’re going to go for a completely different vibe for the next one.

During an onstage Q&A, BM, you said you’d been fearful about being in K.A.R.D and didn’t have high expectations for the group. Why had you thought this?BM: The main reason was that there are no co-ed groups around whatsoever at the moment—we’re the only one. I felt that people were either going to love us or they’d say, "Who are they, I don’t like this, they’re weird." But it turned out that people did love us, so I feel super blessed and appreciative of it.

Everyone talks about K.A.R.D’s international hype, but when did the four of you begin to notice things were getting crazy overseas? J.Seph: When we heard that our Brazil show sold out in two minutes. I really thought, Is this a dream? I couldn’t believe it.

Why is K.A.R.D connecting more successfully than co-ed groups before you?BM: Personally, I think it’s because all members have a unique swag. You look at other artists, and sometimes you think, Hmmm, I don’t know what vibe they’re giving off, but each K.A.R.D member is very distinct. Jiwoo: I don’t think there’s any reason to differentiate artists by their sex. I think it’s because there are a lot of all-boy/all-girl groups in Korea, so we stand out a bit.J.Seph: I think what people enjoy most is the boy-girl-boy-girl chemistry. We’re going to try extremely hard to leave our own imprint in K-Pop.Somin: I think the reason is our songs and our performances.

Somin, J.Seph and BM had been at DSP Entertainment for several years, but Jiwoo, you joined the company and group at the last moment; how did you prepare yourself? And what was the first really memorable moment with your new members?Jiwoo: In the beginning, I worried a lot, but what scared me more was not being able to do music. On my first day, all I wanted was not to be a nuisance to the group; even if I couldn’t become friends with everyone, I wanted to be able to catch up to them. That day was also BM’s birthday, and also my first recording! The members, producer, and the employees all got together and wished him a happy birthday. It was a great beginning.

You must know each other’s deepest, darkest secrets by now...BM: It’s six years now, and I think I know J.Seph’s secrets, but Somin, she was practicing with other groups, so we don’t know all hers. But, yeah, J.Seph and I, we have some pretty dark secrets about each other [laughs].

After six years, is there a habit of J.Seph’s that still freaks you out?BM: When J.Seph sleeps, it’s with his eyes and mouth open, so he looks very awake. I used to come home and be talking to him, and he’d be snoring. All members have lots of photos of him sleeping! [laughs]J.Seph: I think things like sleeping habits and the way a person talks is, in a way, their own kind of charm!

Somin, you guys have been preparing very hard this year. In rehearsals, can you tell us what each member is like? Is there a role they assume?

You guys have already spent so much time touring. What’s something that’s been helping with this amount of shows?BM: When we are in Korea, all we hear is what we need to improve on—your dancing needs to improve here, you need to learn how to do this. And this goes for all K-Pop artists, but being able to tour where we get to receive a lot of love definitely helped boost our confidence, and being able to receive it in another country where the people and culture are completely different has had a very big effect on how we perform on stage.Somin: Just to be given the opportunity to be able to experience something so great is really a study in itself. In the beginning, being on stage was really nerve-racking, but as we performed more and more, it was a lot easier being up there.

Do you talk about your future in years to come or are you making goals you want to achieve quickly?Somin: We always talk about how our big dream is to become world stars. [laughs]Jiwoo: I hope we can promote as units and try different genres as well. J.Seph: We want to receive a new artist award and also take over the music charts, and be a group that people can trust when they listen to our music. I also hope a year from now, even two years from now, that we don’t forget our roots and we remain the same.

BM, which song would you happily claim to have written?BM: J.Cole’s “Love Yourz.” That song is about appreciating what you have and to not focus on what you don’t have. It got me through a lot of hard times in my trainee days, because when you’re a trainee, you don’t know when you’re going to debut. They always tell you, it’ll be next summer, next winter, next fall, spring, it keeps going and going until there’s a set date. Timing is inevitable, they’re going to tell us that, and we’re going to believe it, but there’s a lot of disappointments as a trainee.

Jiwoo, as K.A.R.D's resident fashion killer, you get to design for any fashion house you want.Jiwoo: I don’t know! It’s too hard! I like to try a lot of different styles. I even like brands that are totally different [from each other].

J.Seph, you can time-travel back to any major world event, what do you witness and why? J.Seph: I want to see dinosaurs, but if we’re talking a closer time frame, then the 2002 World Cup. I really want to feel and enjoy that one more time.

Somin, you can have a meal with anyone you want, dead or alive. Who do you choose and what do you talk about?Somin: For me, it’s [Korean singer] Lee Hyori. She’s my role model, and I think I can learn so much from her. Out of foreign celebrities, it’s Ariana Grande. I really love her music. I want to hear her thoughts on our music, and it’s just a wish, but a duet would be a dream come true.