Since I just cared about KAT-TUN very recently (thanks to my Kame obsession).. I just stumbled on this. Granted, veteran fans (or those more obsessed than I am) have known about this a gajillion years ago. I just want to record it here in case I go berserk in the future trying to find the evidence again.
I got this from here.
Then I looked up the songs (Kizuna & Care) and needless to say... I was speechless.