Watch The Sound of Your Heart live: Lee Kwang Soo opens up on his friendship with Song Joong Ki

The Sound of Your Heart, the new KBS drama that stars Lee Kwang Soo in the lead role, will premiere on Friday, December 9, and episode 1 will be a treat for Song Joong Ki fans, as the Descendants of the Sun actor will have a cameo.

Watch the episode live on KBS2 on Fridays at 11:10 pm KST.

The Sound of Your Heart is a sitcom based on a popular webtoon that revolves around aspiring cartoonist Jo Suk (Lee Kwang Soo) and his family. The sitcom has already been released as a web drama.

Lee Kwang Soo recently opened up about his friendship with the Descendants of the Sun actor during a press conference to promote The Sound of Your Heart, and he said Song Joong Ki did not think twice before agreeing to do a cameo.

"I asked him if he could appear as a cameo, and he immediately said yes without having even looked at the script." He then added: "I don't know if there were many ladies present when we were filming, but there was certainly a lot of people."

Producing-director Ha Byung Hoon said the scene with Song Joong Ki is going to be an unforgettable viewing experience. "I asked Lee Kwang Soo to find an actor that was well-recognized and has good acting skills. It was a surprise when Song Joong Ki was cast. I think there was twice the usual number of staff during filming," Ha Byun Hoon said.

Song Joong Ki became one of the most sought-after actors of 2016 following the success of Korean military drama Descendants of the Sun. He played a captain in the South Korean Army who falls in love with an army doctor, the role played by Song Hye Kyo, his rumoured girlfriend in real life.