The popular webtoon transformed into a web drama and was first released online via Naver TV Cast. Starting this month, viewers can watch the production as a new sitcom on KBS. And now with only a couple more days until the broadcast, 'Sound of Heart' shared still cuts of lead actor Lee Kwang Soo or the main character Jo Suk, with close friend and cameo Song Joong Ki. 

SEE ALSO: Lee Kwang Soo returns to SBS entertainment program for the first time in two years

You can check out the first episode of 'Sound of Heart' with Song Joong Ki's special appearance on December 9!