Shim Eun-jin launched her singing career in 1998 as a member of Baby V.O.X, one of the most prominent South Korean girl groups of the 1990s.

[3] She was the first to leave the group at the end of 2004, publicly stating that she did not agree with the direction their record company DR Music was heading.

After a short absence from the entertainment scene, she re-emerged at the end of 2005 with her first solo album, Zeeny's, which was released by the label CJ Music on December 16, 2005.

While promoting her album, she went on various variety shows, and launched her clothing line, Z'BAGO.

[4] In 2006, Shim made her acting debut in the period drama Dae Jo-yeong.