Boy band ZeroBaseOne was given two and a half years from the start. After reaching what was once supposed to be its ending point, the group is beginning anew — this time as a five-member act.

Its sixth and latest EP, “Ascend-,” comes at a delicate moment as the group has nearly halved in size at the height of its popularity, from a nine-member group to a quintet. Yet the remaining five are still looking upward.

“The album’s title, ‘Ascend-,’ signifies moving upward, while the hyphen at the end is also a key part of the album’s message,” said leader Sung Han-bin during a group interview with journalists in southern Seoul on Friday. “The hyphen represents how we are carrying on — now with the five of us.”

ZeroBaseOne debuted in 2023 as a project group consisting of the nine winners of the first season of Mnet’s audition program “Boys Planet” (2023), destined from the beginning to disband after its contracted promotion period of two and a half years.

The contract was later extended by two months into March, when the group held its farewell concert as members Sung, Kim Ji-woong, Seok Matthew, Kim Tae-rae and Park Gun-wook remained ZeroBaseOne, while the other four members — Zhang Hao, Ricky, Kim Gyu-vin and Han Yu-jin — have departed from the group, to debut anew as AND2BLE, along with former EVNNE member Yoo Seung-eon.

The farewell, which Sung described as “the greatest sadness I have ever felt in my life,” took an emotional toll on the group, if the tearful ending of its March concert was anything to go by. But the shift also posed a practical challenge: ZeroBaseOne, which had sold more than a million copies with each of its six consecutive albums since debut, now has to keep that momentum with nearly half its original headcount.

“It would be a lie if I say we had no concerns about that,” Park said. “But those concerns only fueled our passion as a team. As we prepared for this album, our goal became making music persuasive enough that people would want to keep listening to it, rather than focusing on album sales figures and achievements.”

“We do feel a sense of responsibility, but we want to make something that may stay in people’s hearts and memories,” said Kim Ji-woong. “If we can do that, the momentum will follow. What matters most is reaching people’s hearts.”

The group’s sixth EP, “Ascend-,“ comes eight months after its first full-length album, “Never Say Never” (2025), and marks the group’s first new release since the shake-up.

The album features seven songs: the lead track, “Top 5,” and B-sides, “Intro.,” “V for Vision,” “Customize,” “Exotic,” “Changes” and “Zero to Hundred.” “Customize,” in particular, is a song written by member Park, marking his first self-produced song to be included in an album.

The lead single, “Top 5,” leans into contemporary R&B with a minimalistic instrumental, which the group’s agency, WakeOne, described as “a modern reiteration of the 2000s dance pop.”

According to Seok, the song instantly reminded him of Usher, Michael Jackson and Justin Timberlake.

“The moment I heard the tune, I could imagine how the performance would look like,” he added.

“Because the title is ‘Top 5,’ I initially thought this song would be about our declaration going forward,” said Park. “But it’s more about being drawn to someone, which was unexpected. But I think it’s going to be a good synergy.”

At the same time, the group is taking a more stripped-down visual approach, with lighter makeup and everyday, casual outfits in its promotional images — a minimalist turn meant to signal the members’ maturity in the second chapter of their career.

“This time, we opted for a cleaner style rather than something flashy,” said Sung. “What we realized during this album’s preparation was that we still have so many things we want to do and try. So when we put forward minimalism in our concept this time, it meant that we want to preserve what remains inside us — the passion and mindset.”

At its fresh start, ZeroBaseOne is still aiming higher.

“We do want to put our name on the Billboard charts one day, and we also want to perform on bigger stages,” said Park. “As idols, there are still so many dreams we want to achieve and ambitions we have under the name ZeroBaseOne.”

But to realize those dreams, Park said, the group is focusing first on the foundation.

“The foundation for all of that has to be our skills and the quality of our music,” he said. “We are laying groundwork for that now, and I believe this album reflects such determination.”

BY SHIN HA-NEE [shin.hanee@joongang.co.kr]