first of all i love this
i think most everyone would tell him to take it to a shelter 😂 nobara and fushiguro would be like "what are you doing, we can't keep that here" totally logical about it like it is irresponsible for us to try taking care of a kitten as jujutsu sorcerers (even if it's cute and everyone would like to be around it...) I think maki would agree, panda would be indifferent but would enjoy its company.
as for who would try and help him keep it, I think gojo would obviously side with yuuji (both wanting to indulge him and spite fushi tbh), and then i think inumaki would want to help keep the kitten ^^ don't have a proper analysis as to why, it just feels right lol