Someone with Japanese look-up-fu could see if his real name is available in Japanese (Chiba, presumably) phonebooks or listings. (His real name isn't that hard to find (anymore), but you learn more about his family than you do about him when you google it). On the other hand, google-fu-ing his name and thusly finding and contacting his (ex?)wife on twitter is another possibility, though the person who does that might come off as more than a bit creepy. 