Saruhiko is good with his hands.
Typing is one thing, and some people might complain that he's too attached to his computers and gadgets, but Yata loves it, loves seeing the things he's good at it and what he can do with any system, given enough time and plied with enough food to keep him going. (Saruhiko claims he doesn't need the food actually.)
Knives is another, and even when they were at each other's throats, Yata found his eyes drawn to the flick of wrist and fingers, the twirl of blade, silver flashing.
Yata loves to watch those hands.