Lately, achieving an all-kill status on Korean charts is a bit rare, but the musical duo Bolbbalgan4 just proved that they can upon the release of their new title song "Workaholic."

The so-called "perfect all-kill" or PAK is when a song hits No. 1 on the realtime and daily charts of Melon, Bugs, Genie, Mnet, Soribada, and Naver, as well as of Flo's real time chart and the real time and weekly chart of Instiz's iChart. There is also a feat called certified all-kills or CAK when a track ranks No. 1 in all of the music charts except iChart.

The new album marks Bolbbalgan4's fifth mini-album after "Youth Diary 1: Flower Energy" that was released in April this year.

The teaser images of "Two Five" exuded vibrance, with Jiyoung flaunting her new and teal hair color. In one of the photos, the two are spotted sitting on seemingly cinema theatre chairs while the date of the release is written atop them. Their fans, indeed, were excited to hear Jiyoung's soulful vocals and Jiyoon's rapping prowess again, as well as her guitar and bass-guitar-playing skills.

Bolbbalgan4 debuted in April of 2016 with the song "Fight Day," and eventually, they released their mini-album "Red Ickle." From the get-go, they have been making consecutive successes with the music that they offer to their fans and the public.

Their musical career even escalated more when they released their song "Galaxy" four months after their debut, which was then included in their studio album "Red Planet." As a matter of fact, the song bagged the "Song of the Year" award in 2017 Korean Music Awards and the "Best Indie Song" in Melon Music Awards in 2016.

In spite of these impressive feats, the duo showed their humility in an interview with Yonhap Agency in September of 2016.

"I've never thought of us like celebrities. We are just two ordinary kids with ordinary lifestyles," Jiyoung said.

During the talk, the two also explained the reason behind their name. Their Korean name "Bolbbalgan Sachungi" means "Blushing Adolescence." This is most probably the reason why the vibe of their discography is youthful and feels like sunshine.

"Ji-yoon takes care of the 'blushing' part and I go with the 'adolescence' vibe," Jiyong added as she giggled.