To define is to limit. NCT 127 lives by that motto, and the boy group is constantly evolving, whether it be their experimental sound, complex choreographies or intricate concepts.

Since debut, NCT 127 has defied expectations in each release, becoming globally known for its signature "neo" style. Their latest album, "Fact Check", out now, underscores the diverse sonic range of the nine-member band.

"We really put all of our hearts in it," Johnny told USA TODAY about the group's fifth album.

Meet NCT 127

NCT 127 debuted in July 2016 with EP "NCT #127" and lead single "Fire Truck." The group is under the greater umbrella that is NCT, which stands for Neo Culture Technology. Others include NCT U, NCT DREAM, NCT DOJAEJUNG, WayV and a soon-to-debut Japan-based group.

Composed of Taeil (who was absent from the interview due to an injury), Taeyong, Johnny, Yuta, Doyoung, Jaehyun, Jungwoo, Mark and Haechan, NCT 127 is based in Seoul. The latter half of its name represents the longitudinal coordinate of the city.

While the group actively promotes in South Korea, their reach is worldwide. They've toured the globe, received top awards and released chart-hitting records, cementing their spot within an ever-changing industry. The group's last album "2 Baddies" debuted at No. 3 on the Billboard 200, making NCT 127 the second K-pop artist in history to land three albums in the Top 5.

'Fact Check' highlights NCT 127's musical diversity

The multitude of talents of NCT 127 can't be boxed into a specific definition or genre. Fans often refer to the group using "네오하다," which translates to "it's really neo," said Johnny.

"Fact Check" embodies this phrase, featuring the pop rock "Angel Eyes" to smooth R&B "Misty." The nine tracks capture NCT 127's ethos.

"Being as diverse as we can be and being very limitless with our music and our styles, that's the approach we've always had when we start making a new album," said Mark.

"We continue to study in terms of performance, understanding in music, and what concept we'd like to showcase through the tracks. I think that's how we maintain the diversity in concept," said Taeyong, the group's leader.

While working on "Fact Check," Mark said the members considered not only the audible aspect, but also the performance side.

"We wanted to create another great album that would be amazing not just to hear, but to also see on stage," he explained.

The title track, in particular, leans into the group's innovative nature through its kinetic choreography and vibrant tonality. Its music video also give a nod to NCT 127's base with traditional Korean settings. "We went more into our origins throughout the whole title song," said Jaehyun.

Taeyong contributed to its choreography, calling the experience a "really good memory."

Growing through the years

NCT 127 has experienced a lot over the years. They even got to share some of those stories in the docuseries, "NCT 127: The Lost Boys."

"We shared deep secrets; stories that we really didn't say out loud," Mark said. "To share that vulnerability with our audience is something that is great for us to treasure."

Reflecting on growth, each member has developed in their own ways.

Haechan shared how he's grown vocally. "I tend to learn how I can use my voice a bit better and also how to use that into the songs," he said.

For Yuta, he said his confidence has shifted over time. This sentiment was echoed by others.

"Since I joined the team in the middle, I thought I had a lot of lacking points that I had to develop," said Jungwoo, who joined NCT 127 in 2018. "Since the debut, I think now I gained a lot of confidence and also I try to break my limits all the time."

Taeyong said he has gained strength and a better mindset from his members. "When I was young, I was a really sensitive person. It's like I'm so badly pushing myself," he said. "Now, I'm really positive. My members are really helping me."

A humble mentality resonates throughout NCT 127. They strive to become better people as whole, said Taeyong.

"Since debut, there's always limits to when you try to put out some parts that are not close to yourself," Doyoung said. "Right now, I'm trying more hard to be a good person and I think I have become one."

And this process never stops. "I'm always learning more and more about myself," said Johnny. "I am figuring out or have figured out a lot about what I think is important, what I find important, what I think are my priorities."

NCT 127's future is 'limitless'

NCT 127 has a deep devotion for their fans, who they lovingly refer to as NCTzens. In all that they do, the members wish to foster connections with them.

"We want them to remember us as they did the time that they had the warmth in themselves," said Jaehyun, hoping NCTzens hold onto the memories they create together.

As for their music, NCT 127 wants to continue pushing boundaries. "We will never stop our challenges on the musical side," said Doyoung.

And across the board, NCT 127's "future seems limitless," said Yuta.