Eirynne , they performed a bit of Fire Beat prior to Tackey's performance of Hikari Hitotsu last year
you can download the subbed clip of Tackey talk with their Fire Beat performance @
http://newshfan.livejournal.com/140220.html but the Tackey talk is hilarious too with comedians Hannya haha
that will give you a rough idea on how they sound like & yeah they do sound like a mini version of KAT-TUN , from whatever Shounen Club clips I came across of them
my younger sister & I are waiting in anticipation for them to debut & I think I'm not the only one who really wants them to debut like NOWWW D:
They have quite a sizeable fanbase so yeah