why does kakashi cover his mouth part always

[RiaValkyre]

See, the caracter was made like this. Kishi has already said that he regreted making him a mask xD He would not show his face, cuz then somebody would get disappointed anyways.
So it wont be removed. But not because nobody wants it. Just not to make anyone disappointed (I said it after the interview which in he said it)

 

[Chatte]

This reminds me of that episode...

 

[ShadowEXP]

Because he's mysterious.
Bitches love mysterious guys.