BOL4 (also known as Bolbbalgan4 (볼빨간사춘기)) is a South Korean one-member act under Shofar Entertainment. They debuted as a duo on April 22, 2016, with their first mini-album Red Ickle.
On April 2, 2020, Shofar announced that Woo Ji Yun departed from BOL4, and An Ji Yeong would continue to promote under the duo's name, without any additional members.[1]
An Ji Yeong and Woo Ji Yun became friends in high school in Yeonju, Gyeongsangbuk-do. They started a three-member band together with their friend Kwon Ji Won to participate in school music festivals and talent shows. An Ji Yeong was the vocalist, Woo Ji Yun played the bass guitar, and Kwon Ji Won played the acoustic guitar.[2][3]
In 2014, they auditioned for the Mnet survival show Superstar K6 and had a temporary percussionist perform with them during the show. They were eliminated before the top 11 was selected, but they were invited back to do a special performance during the Super Awards ceremony in the semi-final episode on November 14, 2014.[2][4][5][6][7][8]
On April 21, 2015, Shofar Music announced that BOL4 signed with the agency in January.[9]
On May 29, 2015, Shofar Music released an audition notice to find another female guitarist to join BOL4 after Kwon Ji Won decided to leave to focus on her university studies. They eventually decided to have Woo Ji Yun switch from playing the bass guitar to the acoustic guitar and continued as a duo instead.[10][2]
2016: Debut, Red Ickle, Red Planet[]
On April 22, 2016, BOL4 released their debut mini album Red Ickle.
On August 29, 2016, they released their first full-length album Red Planet. The title track "Galaxy" reached rank 1 on the Melon chart on September 26, 2016.[11]