Trouble Maker was a South Korean co-ed sub-unit formed by Cube Entertainment. It consists of Jang Hyun Seung (장현승) and Kim Hyun Ah (현아). The group's debut single "Trouble Maker" released on November 30, 2011, peaked at #1 on GaOn, Korea's official chart, and achieved a triple crown on MNet's M! Countdown and one win on SBS's Inkigayo and jTBC's Music on Top respectively. Their second mini album, "Chemistry", peaked at #1 on Hanteo's Daily Album Chart and the title track