S4 (short for Sexy, Sweet, Smart, and Sentimental) is a four pieces boyband from Indonesia, under training and managing of YS Media & Entertainment, an entertainment agency made from collaboration of Indonesian and Korean people. S4 is the winner of Samsung's GALAXY SUPERSTAR, a talent competition held by Samsung. S4 is consisting of Firly, Alif, Jeje, and Arthur. Their first debut song is "She is My Girl", featuring rap section of HyunA from 4Minute, and the debut music video is posted on YouTube on October 26, 2012 by Mr. Louis Go, Marketing Director of YS Media & Entertainment on his official account. On October 30, 2012, they made their debut stage at VOLUME UP Party with 4minute and Phantom in Jakarta, Indonesia.
S4's first mini album is launched on October 31, 2012 on Melon.com, this release including one new song, titled "Driving Me Crazy" (both in Bahasa Indonesia and English), and instrumental version of "She is My Girl" and "Driving Me Crazy".