Singer Seo In Young made her comeback performance on 'M Countdown' yesterday, but she felt that the performance was a little flat. Seo In Young tweeted, "'Oh My Gosh' comeback. I feel somewhat lacking. Tomorrow for sure! Fighting." She also shared a photo of her stage outfit, posing cutely for the camera. Fans commented, "You were completely pretty and cool on stage," "Your hair and makeup are the best. As expected, a goddess," and "Congratulations on your comeback. I'll look forward to [your performances]." Be sure to check back with allkpop for more coverage on her comeback performances this week! Source + Photo: MT Star News via Nate