Their characters briefly dated on "I Hear Your Voice" and then wound up being good friends. In real life, Lee Bo Young and Yoon Sang Hyun became such good friends that she asked him to sing at her upcoming wedding.

And the way he responded makes it easy to see how much they probably liked to joke around on set.

"Lee Bo Young asked me to sing 'Never Ending Story' at her wedding," said Yoon. "She asked me to sing that song for her parents but I will sing it depending on the way she acts."

Yoon Sang Hyun, who did not make his show business debut until he was 32, initially wanted to be a singer, not an actor. His roles in "Queen of Housewives" and as Oska in "Secret Garden" not only propelled his acting career but also helped launch a singing career. He is now a popular singer in Japan.

To read the article, visit kdramastars.com.