He lowers his hand, momentarily startled by the unusual greeting; he's seen Ken around enough to know this isn't how he usually reacts to things.

But then again, he hasn't talked to Ken much. He has his hands full with the Hamadas as it is (though he does his best to keep an eye on the SEES kids, because they are taking care of Hiro too and it's in his best interests to take care of Hiro's friends).

"Ken-san, is--"

He pauses. He's about to ask 'is everything all right', but it's probably not.

"...are you hungry? I can get you something."

Nailed it.