Young K

He officially debuted as the bassist of South Korean rock band DAY6 on September 7, 2015. On August 16, 2021, JYP Entertainment confirmed that Young K is preparing for his solo debut. On the same day, Young K announced in a V Live broadcast that he would be releasing his solo debut mini album, Eternal on September 6, ahead of his military service.

On July 30, 2023, a first teaser was posted on DAY6's official social media accounts announcing that Young K would be making his first-ever solo comeback since his discharge from the military service with his first full-length album Letters With Notes on September 4. "Let It Be Summer" was pre-released on August 25. On January 29, 2026, KOMCA announced that Young K has been promoted to full membership in the Korea Music Copyright Association.