Haruhi knew that Kyoya like counting. It was a thing he did, calmed him down or something. He wasn't obsessed with debt really, just the idea of more counting (and probably the feeling of power too, because he was a bastard like that). Kyoya saw the world in numbers, careful, complex, measurements and simple binaries. Like a machine, but one that looked pretty and fought dirty.
Haruhi always wondered what he saw when he looked at her. "Mommy" valued cleanliness and order, and she was a hot mess.
Vaguely, she wondered what his binaries would think of her.
Nothing good.
