Overwhelmed by her emotions, JOO shed tears during her�"Bad Guy" performance on MBC's "Quiz That Changes the World." On the show, JOO stood on center stage to perform "Bad Guy", but suddenly stopped and said "I'm sorry" before taking a moment to cry. JOO expressed, "A lot of thoughts came up as it's been such a long time since I've sung on stage. These are all new feelings. To be honest, after I released my first album, I thought I needed more practice and went back to being a trainee." Source: Newsen via Yahoo Korea Tip: kpoplover