Doctor_Whiteface
((Let me ask you something: If you were the oldest living human on the face of the planet with nothing much to do in your spare time, being the appointed diplomat for a group that is, not to put too fine a point on it, the most uncivilized beings in the world, what would you do? Zattenai fills up his time by travelling. He doesn't use the roads often, and his abilities ensure that he's never followed. He's never actually 'met' most people, but he's seen them at one time or another, particularly the really powerful shinobi.))
This statement is completely fallible.
1. Your character would have to have LITERALLY, memorized EVERY single signature he came into contact with. Which unless it's one of your special abilities, is IMPOSSIBLE.
2. You said it yourself, your character has never "met" anyone. Therefore, even by some odd chance of events he was somehow able to memorize that one chakra signature among the thousands he's encountered, he wouldn't know the signature by name, aka: Demon of the mist, or Zane. So you really did yourself in with that statement.
3. Finally, his past has no correlation with Zane. As such, unless it has been RP'ed that he bumped into Zane somewhere, you've never bumped into him on a technical standard.