Two Five will be the duo's return after the release of their 4th mini-album, Youth Diary 1: Flower Energy, in April this year. It is slated to be unveiled on September 10, 6:00 P.M. KST. Fans are currently gingered up on this new concept as their last comeback was different, floral, and preppy. 

Bolbbalgan4 - comprised of Woo Ji-youn and Ahn Ji-young - debuted with their extended play Red Ickle in 2016. They first made their appearance on the sixth season of the audition show in tvN, Superstar K, back in 2014. 

Ahn, being the main vocals that she is, is known for her charming voice and her unique style of singing. Woo is equally talented as the Ahn, a proof that they are just rightful to be in the same singing team.

Among their past hits are Tell Me You Like Me, Hard to Love, Bom, To My Youth, and Travel, which achieved a Perfect-All-Kill in charts in 2018.

With their sugary and youthful music, it's not surprising that the duo is widely recognized domestically and gradually sneaking their way internationally. They then opened up their thoughts on this with Billboard last April.

"The reason why we can get this huge support and love is because of the singers who previously have contributed a lot of efforts to spread K-pop worldwide," Ahn began.

"As we get more views on our music videos and can see different languages on the comments, I can see that people around the world who love our music is increasing. So, we would like to have more international concerts than last year. I want to give a lot of thanks to international fans who support us from far away," she went on.

They also expressed their gratitude to their fans.

"I feel so grateful to have you love and support our latest album again. Like this Billboard interview, one day I can be on stage in America, too! I hope we can meet in a lot of different places. Also, we will sing more good songs for you so on. I hope you enjoy a much more special and happy spring with our spring-like songs!" Ahn said.