After Spike and Kirk, it's got to the point today where he's started assuming that every unfamiliar female he's met is usually a man. So when he comes upon this girl stomping around and notes all Kanji's usual distinguishing features, it's not a difficult job to figure this one out.
"Kanji?" he asks carefully, wincing slightly at the thought of what this latest game of the warden's might be doing to his not!son's rather fragile confidence in his own sexuality.