Comedian Yoo Sae Yoon's single album song, "Gga Ddok," is unveiled.

On October 16, 2013, Yoo Sae Yoon revealed his second digital single, "Gga Ddok," through various online music websites.

"Gga Ddok" is a song that tells a story of a man who is desparate for his girlfriend who is always so engrossed on Kakaotalk and doesn't even want to talk to him. This medium tempo acoustic hip hop ballad shows off witty lyrics that Yoo Sae Yoon personally wrote.

Im BoRam from Mnet's Superstar K3 recorded the featuring female voice for the song. This is a second single album song since "This is Art," a song he revealed on Mnet in the past.