[He should have explained a few things first, probably-- that reaction definitely reminds him, and Hizamaru raises his hands slightly in the universal gesture for 'please don't panic'.]

Ah- well, this body hasn't existed for very long? I'm actually a little over one thousand by now...

[A very helpful answer, thanks Hiza. One hand settles on the sheath of his sword as he continues.]

I'm a tsukumogami. A more recent master of mine was able to give us bodies to fight with, but I couldn't tell you why we manifest looking the ages that we do-- it isn't anything I've ever questioned.