Kitty will actually pay him a first visit this week, on a night when Tobias is wherever and the temperatures have gone very low, so that it seems wiser to not strain the heater and instead steal some warmth from Ryoji. She lets herself in (sure, the door is locked, but she is invited, so it's not like she's breaking and entering if she picks the lock and sneaks inside, right? Especially if she locks the door behind herself again... And is extra careful that nobody sees her.

She changes back into a cat as soon as she doesn't need her hands to handle a lock pick anymore, tucking it safely away under the kitchen counter, and then pads around until she has found Ryoji and just jumps up - into his lap if he's still awake, and just on his chest if he's asleep.