Sung Si Kyung and IU have released their first, short MV teaser for their first duet in approximately 9 years!

Titled "First Winter", Sung SI Kyung and IU's upcoming duet single will be a warm, emotional winter theme song. Back in 2010, the two solo artists worked together for Sung Si Kyung's "It's You", and now, they've decided to test their chemistry once again with "First Winter".

Sung Si Kyung x IU's "First Winter" is set to drop via various music sites this December 9!