Mighty Mouth has released a new version of their song "Tok Tok", which features the vocals of Kim Bum Soo. Currently, this dynamic duo is in the midst of promoting their original version of "Tok Tok", which guested singer Soya. According to Mighty Mouth's management company, if Soya's version is clean cut and powerful, Kim Bum Soo's version will show more freedom, as he's a veteran in the industry with perfect control over his vocals. The agency also revealed that Kim Bum Soo's version was actually the 'true' original, but because there were some scheduling difficulties, the singer would not have been able to appear alongside Mighty Mouth for their promotions. Consequently, both parties decided to put out Soya's version as the 'original.' Check out the 'true original' of "Tok Tok" below! Source: Newsen via Nate