Bolbbalgan4

Bolbbalgan4 (, also known as BOL4 or Blushing Youth or Blushing Puberty, pronounced Bolbbalgan Sachungi) is a South Korean musical act formed by Shofar Music in 2016. They appeared on "Superstar K6" in 2014 before signing a contract with their current agency. BOL4 was originally a duo consisting of Ahn Ji-young and Woo Ji-yoon. They debuted with the single "Fight Day" from the mini-album "Red Ickle" on April 22, 2016. The meaning of 사춘기(思春期) is "puberty" in English. In Korean, the pronunciation of 사(思) is the same as 사(四=4), so the group name is sometimes shortened to Bol4.
The duo went on a temporary hiatus due to Ahn's music classes requirements in the first half of 2018. Bolbbalgan4 signed with King Records and debuted in Japan on June 5, 2019, with the mini-album "Red Planet (Japan Edition)".
On April 2, 2020, Shofar Music announced that Woo Ji-yoon had left the duo, and Ahn Ji-young will continue to promote as Bolbbalgan4.
Formation.
Jiyoung and Jiyoon were both raised in Yeongju city, Gyeongsang, and were classmates. They had previously competed SuperStarK6 in 2014. Since they were young they had dreamed of becoming singers. The name of their duo was built on the grounds that they wanted to make the kind of pure, honest music that can only be found in adolescence. Jiyoon portrays the "blushing" part of the name because she is often shy, while Jiyoung portrays "youth" because she acts like an adolescent girl.