Ogasawara Islands (Bonin Islands):
500 miles south of Tokyo, rose from underwater volcanic chain. You will be on board "Ogasawara Maru" more than one day to get there. But it is a wonderful place worth for the time. Here's some photos from my album. (Ogasawara Diving Related Information )

Some sites are 2 hours boat ride from main island.

Drop in the middle of big school of fishes and forget descent.

Sometimes currents are very strong.
You just have to dive head first
straight to bottom.