[King of Mask Singer' f(x)'s Luna, Kahi, BTOB's Sungjae, Kim Hyung Suk to guest on 'Radio Star' Unknown 3:30:00 PM BTOB, f(x), Kahi, Kim Hyung Suk, Lune, radio star, Sungjae Comments 'King of Mask Singer' contestants will be making their guest appearance on MBC's 'Radio Star'. According to multipl... Read More Share: