Of those present, bassist Lee Jae-jin looks at the interviewer with a curious grin but becomes a little alert when their eyes meet. Choi Jong-hoon, guitarist and keyboardist, and Lee Hong-ki, vocalist, are enjoying their “time off,” jamming on an acoustic guitar and sitting quietly as the hair and make-up crew put on their final touches.

They are stars, their faces mostly inexpressive — impenetrable. Or maybe they are just tired from their 20-hours-a-day routine that began with the newest EP release earlier this month.

But they are also just young men who are reaching their 20s. When all five reunite at last, with Choi Min-hwan, drummer, and Song Seung-hyun, guitarist and vocalist, they become a playful gang, cracking jokes about each other’s pet peeves or latest love interests.

“You know, I didn’t even know singers needed to go to a throat doctor until (an older singer) told me,” said Lee Hong-ki, 21, underlining both his inexperience and his goal of a long-lasting career. “Our range of music — what we can see and hear — is expanding. As a band, we’ve reached our comfort level. We are used to each other’s habits when we perform together.”

They say they are “Grown Up,” like the title of their latest disc. But they constantly reassess themselves in a strikingly carefree, frank and joyful manner. They have a five-year career, “veterans” by this fast industry’s standards. They have built multinational stardom on a string of No. 1 hits and drama appearances.

But, as all members only just graduated from high school, they say they are still hungry for growth. They attribute this to their curiosity, musical and personal.

“When we are in Japan, we can see how much we are improving because the members write the words and the music. We sing what we really want to sing there,” said Lee. “There are so many bands, so many opportunities, so many rehearsal studios.”

“For Korea, we have to worry about (songs’) addictiveness,” said Lee Jae-jin, 20. “Without that it’s hard to be noticed.”

This particular formula heavy on hooks has been credited as the driver of K-pop’s success overseas, yet the band seemed intent on distancing itself from the phenomenon.

“I want our band to be known (in other countries),” said Choi Min-hwan, 19, “not riding on hallyu but independently.”

And F.T. Island can lay that claim — albeit partially. At the height of their fame in Korea in 2007, which was instant from their debut in the same year, the band moved outside their comfort zone to Japan, playing for 100-strong audiences in small venues there.

Their major success came with the Korean wave, though, as the band’s popularity was propelled by the hit Korean drama “You’re Beautiful” that starred Lee Hong-ki. It led to a record deal with Warner Music Japan in 2010.

Despite this power of Korean idols, F.T. Island stays modest, reminding themselves of their initial years as unknowns.

“The Japanese audience is so quiet when you perform,” said the vocalist-cum-actor. “You can tell the reception very clearly. We were scared (in the beginning). In Korea, everyone applauds as soon as you’re on stage.”

There have been lingering doubts about their musical depth, with critics and anti-fans calling them “a fake band,” thanks to their boyish looks and attention to style.

“We ignore them (the critics) now,” said Choi Jong-hoon, 21, decisively. They used to question themselves constantly over the definition of a real band at the beginning of their career, he said. No more.

“What is a real band, then?” said Lee Hong-ki, interrupting.

Regardless of the label, they find inspiration in unknown territories. Last September, F.T. Island performed in Toronto at a benefit concert for the victims of the Tohoku earthquake and tsunami in Japan. The members had a chance to interact with other bands participating — and experienced culture shock.

“There was a European band,” said Lee Jae-jin, “where every member had a different nationality. How did they meet?”

To the members of F.T. Island who started playing music from their middle school years — within a system — a concept of garage bands seemed so enviable.

“They seemed to have so many people around them who share the passion for music. I was impressed,” said Lee Hong-ki. “As a normal school (student) band, it would be difficult to go on.”

While they described the scene, about conversing through an interpreter and swatting mosquitoes together, the pace of their speech quickened and their eyes sparkled, even as the 90 minute interview drew to an end.

They were unable to hold their breath, excited to discover the whole world ahead of them — meanwhile gushing about how a fellow singer they met in Canada looked like Johnny Depp or Orlando Bloom.

Before the interview was over, they insisted that this reporter dedicate a few lines to the fan club Prima Donna.

“When we put everything together, we learn so much. We want to take more lessons, too,” said Lee Jae-jin.

“We just want to make awesome music. We don’t want to think of it all as complicated,” said Lee Hong-ki, responding to the question of their future direction and adding that his favorite genre at the moment was punk rock. “We want to do the music that fits our age, not sticking to one style or genre. We want to go with our feelings.”