K-pop boy band BOYNEXTDOOR dipped into the members’ personal stories for the tracks on new EP 19.99. Singer Taesan tells Billboard that the seven-track mini-album “explores the emotions experienced just before turning 20. Specifically, the tracks express the intricate emotions that precede and follow turning 20.”

Group leader Jaehyun adds that the album is especially close to the singers’ hearts because it involves a lot of “true stories” from their personal lives. “We felt a lot of some kind of pain, some kind of happy and some kind of thankful. We always feel pain of growth, growing, so that is our album’s story,” he says.

The EP that dropped on Monday (Sept. 9), was preceded by the uptempo single “Dangerous,” which the group says represents their “mischievous side,” in which they fantasize about such rule-breaking activities as not listening to their moms, hanging out with friends all night and other shenanigans they pulled off before turning 20. And while their aim was to express a wide variety of feelings in a uniquely BOYNEXTDOOR fashion, boys also, of course, just wanna have fun.

Then again, lead single “Nice Guy” presents the flip side of that dangerous attitude, with lyrics Jaehyun says are funny and witty, which, of course, would not be as funny if they were all in their 30s. (All of BOYNEXTDOOR’s members — which also include Sungho, Riwoo, Leehan and Woonhak — are between 17 and 20 years old.) “But we are 20, or 19, 17, so I think that point is a really good point and ‘Nice Guy’ is [like a] flirt to someone,” he says.

Because the members of HYBE’s latest boy band write and co-produce a lot of their songs, Taesan — who co-wrote and co-produced “Dangerous” — says he also incorporated a lot of his own stories and an anecdote involving one of his siblings on the EP that focuses on “real-life experiences” rather than more generalized pop culture references from TV and movies. “We tried our best to use lyrics and melodies that feel genuinely relatable from our everyday experiences,” he says.

BOYNEXTDOOR scored its highest charting album to date in the U.S. when How? entered the Top Album Sales chart at No. 7 on the May 4-dated tally. The group released its first single album, Who! in May 2023, followed by the EP, Why.., in Sept. 2023 and this year’s How?

Watch BOYNEXTDOOR’s interview with Billboard above.