He and his SS501 members appeared in Park Kyung Lim's show Thank You For Waking Us Up and Thank You For Raising Us in 2006, where he proved to be a heavy sleeper.
He joined the cast of MBC variety reality show 'We Got Married' on 11 May 2008, with Hwang Bo, who is 6 years his senior. They achieved high popularity, garnering attention to Hyun Joong especially, after which he was chosen to be casted in the Korean version of 'Boys Over Flowers(or Boys Before Flowers)' (TV Series)/Hana Yori Dango as one of the members of the infamous F4.
Hyun Joong and Hwangbo made their official exit from We Got Married on December 14, 2008.
He is to portray Hanazawa Rui, renamed Yoon Ji-hoo, in the upcoming drama 'Boys Over Flowers(or Boys Before Flowers)', which is set to air on January 5, 2009 on KBS.
Due to the busy schedules, SS501's album was pushed back to April 2009, and instead a subgroup Triple-S, consisting on members Kim Hyung Joon, Heo Youngsaeng and Kim Kyujong, will continue activities with the release of a mini-album titled U R Man.