Lee Mingi is a genius rocker, as well as leader, vocalist, and guitarist of a rock band called Ex-So (Excellent Souls),that he founded together with drummer Han Gijoon. The cynical Kang Hyeok is the keyboardist of the band, but also a medical school student who is from a family of doctors for many generations. The two will be involved in a love triangle with the lead female. Meanwhile, Yoo Hancheol is the bass guitarist.

• Lee Hong-gi
• Park Min-woo
• Lee Si-eon
• Kwak Dong-yeon
• Lee Ha-nee
• Lee Han-wi
• Lee Il-hwa
• Kim Bu-seon