(Korean: 발칙하게 고고; RR: Balchikhage Gogo; lit.

Sassy, Go Go) is a 2015 South Korean television series starring Jung Eun-ji, Lee Won-keun, Cha Hak-yeon, Ji Soo and Chae Soo-bin.

It aired from October 5, 2015 until November 10, 2015 on KBS2 every Monday and Tuesday at 22:00 KST for 12 episodes.

Kang Yeon-doo (Jung Eun-ji) is the leader of outcast street dance club "Real King", a group of students who band together because of their poor academic performance, whereas Kim Yeol (Lee Won-keun) is the President of "Baek Ho", an elite club composed of students from the top 5 percent.

is a story that aims at ordinary high school students' misadventures including love, heartbreak, pain and friendship.