Well I don't think that there are any real "Ninja" today. Maybe with the exception of Hatsumi-Sensei. But as for Jinichi Kawakami I know that he is affiliated with that hombre...Juan Hombre. So that in itself makes me question his claims. Not to mention that I haven't seen anything to who actually trained him in Ninjutsu.
I don't know 'Juan Hombre' so I won't comment. He is from South America? I agree that expert in Ninjutsu is seperate from Ninjya. It also rests on your classification. Not 'TV Ninjya'. 'Nin-jya' has specific spiritual, martial art, special knowledge etc category and ability, so it can be known. I can see currently alive, Tanemura Shoto, Hatsumi Masaaki have respect in all these areas, but I also know families who also have this. So 'Last Ninjya' claim is something to say with no understanding.
Kawakami Jinichi is Ninjyutsu expert, but this is due to research and performance. There was a TV program in Japan about his lifestyle, but this was for entertainment. So I can't comment on his personal life, only on his knowledge and dedicated practice and research. There are many people deeply practicing who are not known, so I think broad statement is not right.
Thankyou