You really wanna go there, Old man? You might be my gramps but I’m not afraid to go ‘Ora Ora’ on your wrinkly ass.

Put. It. Back.

“You… Old man, put that back where you found it. And don’t tell ANYONE.”

“I know it sounds ridiculous, but it’s true. Things are always this strange. Is the previous existence of a 100+ year old vampire really that shocking to you?” Jotaro asks with a quirked brow, honest to God shocked that Rohan’s the one in disbelief. He supposes there is a way he can prove it, but he’s not entirely sure he trusts the mangaka to read about Dio and only Dio if Jotaro gave him the chance to read him.
“Do you need to read me to confirm it? I have no reason to lie about this.”

Jotaro blinks, his eyes groggy from having them closed in his attempt to sleep, only he couldn’t. The air was dry and cold, the rickety sound of the car driving along coupled with Polnareff’s heavy snores distracting him. He didn’t even think Kakyoin was still awake, so the sound of his voice (gentle, concerned) was a surprise.
“Sorry. Did I wake you? I guess I’m just sort of cold,” he says, voice low to not disrupt the snoring man sitting in front of him (or his grandfather who was driving, no doubt kept up by the quiet hum of the car’s radio. “And I can’t sleep.”

Jotaro lifts his hand to take her tiny one in his, but just as he extends his index finger Shizuka’s suddenly disappears. He’s startled at first, but then comes to recall that she does that sometimes. He remembers Joseph saying she starts turning invisible due to negative feelings. Perhaps she’s hungry? Or just learned to control it, but he doubts that… She’s still a nearly a baby, after all.
“Do you need milk? Or…” Jotaro’s face slowly morphs into one of slight mortification upon realization that she might not be hungry but need a new diaper. Ugh, why did the old man leave him to babysit? He hated changing diapers… “Did you shit yourself?”
Regardless, he takes a hold of Shizuka’s bottle from earlier, handing it over to her in the hopes that she just needs to be fed again.

Seemed.
Jotaro doesn’t personally know this girl all that well, but she was helping them. She was innocent in all of this, had no idea what she was even helping them with when Jotaro questioned her a few days prior.
“What did you do with her?”

“I’m not fond of beating around the bush. It’s annoying and wastes time, especially when there are more important matters to worry about. I thought you were aware of this already from our previous run in with each other.”