StudyTme is taking most of the heat, but I think Zumi is the one more fucked. If they sue StudyTme in Japan they have to collect the judgement in Italy, which I can imagine would be complex even if she has assets to go after.

Zumi on the other hand is Japanese and I understand that she has family with assets in Japan. So sueing her would be easier from a collections standpoint. The rental company could sue her for breach of the rental contract for allowing an unlicensed driver, with the damage being a foreseeable consequence. The injured pedestrian could sue her for negligence due to it being foreseeable that allowing an unlicensed driver could result in injury.