There is a longstanding question in K-pop about what actually holds a girl group together: a single breakout star, a concept strong enough to carry eight people, or something harder to manufacture. Hearts2Hearts, the SM Entertainment octet now 16 months into its career, is proof of the third option.

The group’s structure is built around what it refuses to do. Instead of one designated center, Hearts2Hearts spreads the weight, arranging vocal lines, choreography and camera time so that individual moments serve the whole. It’s a familiar pitch in K-pop marketing and a rare thing to actually pull off. What sets this group apart is that the balance holds up under scrutiny, onstage, in live vocal takes, in the self-produced content where group dynamics usually crack first.

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Even the group’s most viral moment worked this way. Stella’s spoken English narration in “RUDE!” became the song’s signature and fueled a fan challenge, yet it never read as one member breaking away from the pack. It read as Hearts2Hearts. That house-leaning single, released this past February, climbed to a No. 57 peak on the Billboard Global 200, while rising to No. 5 on the Billboard Korea Hot 100. The demand followed offstage: in March, the group sold out showcases in both New York and Los Angeles. For an act barely a year past its debut, which reached No. 102 on the Billboard Global Excl. U.S. chart with “The Chase,” that is a group finding its ceiling and pushing past it.

“Lemon Tang,” the title track of the second mini album released June 22, carries that momentum into a bright, summer-coded dance-pop turn. Where “RUDE!” came from a team of Western topliners, the follow-up is a KENZIE record, penned by the SM in-house veteran whose credits run from Girls’ Generation’s “Into the New World” through two decades of the label’s girl-group canon. The chorus leans into a breezy, bossa-inflected sway, and the vocal arrangement follows the group’s usual logic: lines sung in pairs that build into all eight voices in unison. The lyric’s central image, a lemon that is sour alone and turns sweet in combination, is also a fair summary of how this group operates, name included.

That’s the thing about Hearts2Hearts. The appeal is cumulative rather than explosive: friendly without being lightweight, bright without being simple, and consistent in a genre that usually chases spectacle. In this interview with Billboard Korea, the eight members talk through the moment they first saw their name on the Billboard charts, the energy of their first sold-out U.S. stages, the roots each member brings to the team, and what they hope people understand about Hearts2Hearts by the end of this summer, in their own words.

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From “The Chase” to “RUDE!,” sixteen months have already passed. How do you feel about where Hearts2Hearts stands now?

JIWOO: I think we’re still in the middle of growing and learning, but when I look at where we are now, I’m most proud that Hearts2Hearts is starting to have a distinctive color of its own. We’ve gained a lot of experience since debut, and I think we’re becoming more confident both as individuals and as a team. It makes me excited for how much more we can grow from here.

YE-ON: Like JIWOO unni said, I think we’re still growing as artists. But if I had to pick the biggest change, it would be how much more comfortable I’ve become on stage. At debut, I was focused on finding the cameras, but now I feel more confident connecting with our fans and enjoying the moment!

Hearts2Hearts arrived as SM’s first new girl group since aespa. Did that description ever feel heavy to you, or did it become a quiet source of strength?

YE-ON: Rather than feeling pressured, I think it motivated us to work even harder together so we could live up to people’s expectations. It felt more like positive encouragement that pushed us to keep practicing and improving!

When you first heard “Lemon Tang,” what made it feel like the right next chapter after “RUDE!”?

YUHA: The track carries the same confident energy as “RUDE!” while bringing a brighter and more refreshing feeling that fits the summer season. While “RUDE!” was about breaking away from expectations and doing things our own way, “Lemon Tang” shows a brighter side of us and celebrates how beautiful it feels when we’re together. That’s why it felt like the perfect next chapter.

“Baby Steps” carries the excitement of a new beginning, while “Secret Recipe” tells a story of building something together. Which track feels closest to the team’s heart right now?

JUUN: I think “Baby Steps” feels closest to where we are right now. As we begin this new chapter with “Lemon Tang,” I think the excitement and nervousness of trying something new really reflect how we feel as a team. That’s why I find myself relating to “Baby Steps” the most.

“RUDE!” reached No. 10 on Billboard’s World Digital Song Sales chart and entered the Billboard Global 200 as well. When you first saw Hearts2Hearts on an overseas chart, what went through your mind?

CARMEN: I’m so, so thankful to S2U and to everyone who has been listening to “RUDE!” I’m incredibly happy, and honestly, it still feels a little like a dream. Seeing our song on the Billboard chart was… just wow. It was such a huge moment for us! I’m truly grateful for all the love and support. Thank you so much!

STELLA: When I first saw “RUDE!” on the Billboard charts, I was really shocked and so grateful for all the fans who supported us. It really made me realize that there are so many global fans who love our music, and it inspired me to work harder for our next comeback.

Stella, your English narration became one of the signatures of “RUDE!” and even carried into the challenge. Did you expect that part to resonate with listeners in that way?

STELLA: When I first recorded the narration part in our song, I had hoped that our listeners would resonate with it. However, I didn’t expect the amount of love and attention that it would get at all. Watching our fans and listeners do the narration challenge was so much fun, and I feel incredibly grateful for all the support.

In March, you sold out showcases in both New York and Los Angeles. What felt different about the energy of the U.S. fans compared to the audiences you had met in Korea?

A-NA: All of our fans are incredibly passionate, but what stood out to me in the U.S. was how loudly everyone sang along and even danced with us. Seeing the crowd enjoy the music so freely and express themselves in that way was really new and memorable for me.

IAN: The showcase was a moment where I really got to feel the incredible energy of our fans in the U.S. Even the smallest things we did got such a big reaction. Hearing everyone sing along and seeing them jump and have fun with us really made me feel their passion.

Jiwoo, as the leader, what did the “RUDE!” season teach you about the members that you may not have fully realized before?

JIWOO: During our “RUDE!” promotions, I realized once again how strong and dependable our members are. I was really impressed by how everyone took responsibility for their own role and always gave their best. Even during difficult moments, the members were always looking out for each other first, and I was so grateful for that. It made me trust the team even more, and I felt just how reliable everyone is.

Carmen, as SM’s first Indonesian member, what kind of color do you feel your roots bring to Hearts2Hearts when the group connects with fans around the world?

CARMEN: As SM’s first Indonesian member, I’m really grateful to be able to share a part of my culture and experiences with Hearts2Hearts. Growing up with a different background has given me a broader perspective, and I think that helps our group connect naturally with fans from all around the world. I also feel happy that I can introduce Indonesia and represent many fans who dream of standing on a global stage. More than anything, I hope the warmth, sincerity, and positive energy I’ve grown up with can become one of the unique colors that make Hearts2Hearts even more special.

The name Hearts2Hearts carries the idea of connecting one heart to another. Since your debut, what has been the clearest moment when you truly felt that connection with your fans?

A-NA: One of the moments when I feel most connected to our fans is when I see them smiling and enjoying themselves while watching us perform on stage. Seeing that happiness on their faces makes me feel like our hearts are really connected.

The rookie season often passes faster than people expect. Is there something you feel Hearts2Hearts can only do now, precisely because you are still at the beginning?

IAN: I think it’s continuing to show how we’re growing. All of the members constantly give each other feedback and always want to improve, so I think people can really see that growth through our performances and activities.

By the end of the “Lemon Tang” promotions, what do you hope people will understand a little more clearly about Hearts2Hearts?

YUHA: Just like the feeling you get when you think of “Lemon Tang,” I hope thinking about Hearts2Hearts can make people smile and feel a little happier.

JUUN: Just like the lyrics of “Lemon Tang,” I hope people can feel that fresh, uplifting energy with us. I also hope our song becomes the soundtrack to everyone’s summer and helps make this season feel a little brighter and more fun.