Her first big break came when she starred as David Tennant's eldest daughter in the television series Single Father.
single | single (music) | Single (music) | hit single | father | Catalog numbering systems for single records | Single-elimination tournament | CD single | Father's Day | Father | Father of the Bride | Mother Father Brother Sister | Father Knows Best | Father Ted | The Courtship of Eddie's Father | Romulus, My Father | Father Damien | Father Brown | 12-inch single | Father Yod | Single-lens reflex camera | Living Single | Hit single | God the Father | Father Time | Father and Son | Bachelor Father | 2012 World Single Distance Speed Skating Championships | The Father (Strindberg) | The Father |
In 2004 he was cast into the ABC sitcom, Complete Savages, where he played fifteen-year-old Sam Savage, one of five teenage boys being raised by single father Nick (Keith Carradine).
Joo starred in the 2004 film Family alongside Soo Ae, portraying a single father who has a troubled relationship with his daughter.