There was a report recently that two Japanese soldiers were still yet to come in from the hills of Mindanao in the Philipines:
Yoshio Yamakawa, aged 87, and Tsuzuki Nakauchi, aged 85.
Although I don't know if this ever proved to be a hoax or not (as had been suspected).
Apparently Japs doing this sort of thing was fairly common Hiroo Onada being the one most people have heard about. Bizarrely, his story was the theme of the concept rock album 'Nude' by the prog-rock band Camel.
More info on Jap WW2 holdout soldiers here if you are interested:
http://www.wanpela.com/holdouts/list.html