I've never heard of Neko Appeal, and Kuro has sported nekomimi before, perhaps that's why you get reminded of some sort of cat when you see her. Also, fangs.
PS: Besides, we're clearly talking about a cow here.
Obviously you'll never heard of it, because in a way it 'didn't exist.' Clearly put, I felt like using it as a term because it'll sound like one. My explanation will sound very cliche because it's exactly what it'll say on the tin, so yeah. (Note I was referring to all 3 KnJ characters, not just Kuro, thus stressing <given examples> further. And I gave more than one series example, saying that said 'term' isn't limited to one character)
EDIT: For those who didn't get it: Nekomimi accessories aren't the only thing making neko-themed characters.
....... I'm just explaining, not forcing. Mileage will vary anyways.