The reliable Ressac, the mild-mannered Flows, the frivolous Shuplu, and the boyish Bubblin make up the rich pallet of personalities of this 4-man unit. No one can particularly pick out which color, voice, or even personality appeals to them the most individually. Also, even if their relationship with each other is pleasant even in private, the four of them being seen playing together often becomes a topic in news and tabloids. And the reason none of them go solo is entirely of their own provocation, and not that of the head office, as they said "I don't want to do work if it's not the four of us together".

During Live Shows, as fans wave their glow sticks, the light changes to the corresponding light of the one currently doing their Solo act of the songs. It is said they are apparently "very well-trained fans".