On the afternoon of August 18, Brand new Music released the concept photo of GREE's new single 'Humming' through official social media channels, attracting attention. In the photo, GREE is a mature figure, boasting a full-fledged visual, and the attention of fans.

GREE's new single 'Humming' is a Brit-pop genre song that contains the moment when a separated lover faces the appearance of being with someone other than me, leaving behind the fluctuating emotions and comforting himself by pretending to be okay. New Producer On the Road, following the last single' HIM', joined GREE as a co-producer again.