Rookie group�F.I.X kicked off their 'Music Core' debut with a strong performance of "Please Don't Say". The vocal quartet poured their emotions into their performance, leaving the audience spell-bound with their rich ballad. F.I.X. drew a lot of interest both local and international, thanks to the cameo�Super Junior's�Eunhyuk made in their music video, which you can watch�here. In the meantime, check out their performance below: