Im not sure if this is a secret so yeah...............
Ok well I was watching an episode thing called "Konoha Sports Festival" (I think) and Naruto had to go to the bathroom. So you see him run into the hall only to see a huge line. When they show you who's in the line, Im not making this up, Itachi and Kisame are BOTH in line to use Konoha's bathroom. Seriously.....my reaction was:
-O_O
-Why are they still there???
-^_^ YAY ITACHI!!!!
It was the weirdest thing.......try watching it. For best results try Youtube.