BOL4 (볼빨간사춘기) is a South Korean indie band signed under Shofar Music and King Records. BOL4, which is loved by many for expressing the feelings of a “shy adolescent girl,” was originally a duo composed of Ahn Ji-young (Vocal) and Woo Ji-yoon (Guitarist).

BOL4 made their first public appearance on the singing competition show, “Superstar K6.” After the show, Ji Yeong and Ji Yoon received contract offers from various agencies before settling with Shofar Music.

On April 2016, the group debuted with their first mini album called Half Album RED ICKLE, followed by the release of their first full album, Full Album RED PLANET. The title song, “Galaxy” began to gain acceptance after starring in “Yoo Hee-yeol’s Sketchbook.” The song entered the Korean charts just a month after its release, and eventually climbed to claim the #1 spot for multiple weeks. After the release of the album, the hit track “Tell Me You Like Me” topped the real-time charts as soon as it was released.

On April 2020, Shofar Music announced the departure of Woo Ji-yoon from the duo and that Ahn Ji-young would continue performing as a soloist.