The music was composed by Jellyfish Entertainment CEO Hwang Se Jun and Swedish production team D30 (Caesar & Loui and Olof Lindskog).

[citation needed] The song peaked at number 35 on Gaon Singles Chart.

[1] The lead single from Jekyll, "G.R.8.U" (Korean: 대.다.나.다.너; RR: Dae.da.na.da.neo), was written by Kim Eana and produced by Hyuk Shin, DK, Ross Lara and Todd Wright.

[citation needed] The song's music video was directed by Hong Won-ki of ZanyBros.

[citation needed] Promotion began on August 1, and wrapped up with a goodbye stage on Inkigayo on September 8.