I am also surprised why he decided to remain hidden in the dark. He has created something amazing, which is Bitcoin that trying to change the face of our traditional finance system known notoriously expensive and complicated. Clearly, by his name he is a Japanese, but who know right? Maybe it is just a pseudo name. I think he remains mysterious because initially Bitcoin was used in the dark web by criminals and he doesn't want to get involved in it. It is my opinion though.