[On one hand, he doesn't react like this is a foreign term, if only because he himself is a youkai of sorts - a creature that most assuredly doesn't exist to most humans outside of their own legends, just like any other inhuman thing.

On the other hand, he immediately says:] I see... The Matsui clan... At that time, they would be in Shinano, just south. Even so, if human envoys were sent to you... Existences like you or I don't interact with humans, in the world that I know.

[There is perhaps the faintest, faintest hint of something in his tone which indicates that he knows this is not the reaction she was hoping for. He's nothing if not honest, though.]