To get back to the original question, recent research has show there were several inflows of people into Japan. Some of these overlapped, some of them were repeated many many centuries later.
At a time when Indonesia was still connected to the rest of Asia, there was a large inflow of people from there. Most of them arrived via a sea route. Other inflows came through what is now Korea, and North-East Asia. There was actually a time when what has turned into the northern island of
Hokkaido was connected with the mainland of Asia. A similar landbridge existed between Asia and the Americas. This allowed peoples to cross into the Americas and eventually move to the most southern tip.
After sealevels rose millions of islands were created, seperating people and thereby allowing them to develop cultures independent of each other. So where do you start Japanese history? If you go back far enough we all come from the orginal Eve somewhere in Africa. This is a history we all share, whether we are aware of it or not.
I guess Japanese 'history' started when the people here began developing cultures sufficiently different from the ones they originated from. When exactly this happened is still an ongoing quest for scientists. In the past few years there have been many surprising finds in
Kyushu where a flourishing culture developed at an earlier stage than was believed possible. Unfortunately 20th century development has destroyed most of the escavating sites, and even now only a few are protected for the future.
For more information, check out these links:
Revolution of Ancient History --
The Furuta Historical Science Association considers many Japanese history textbooks "dishonest". It publishes research papers like The Self-Evident Truth About the Jomon Stones.
Ancient Japan --
Also mentioned by Mindy in an earlier posting in this thread. From Richard Hooker's World Civilizations series. An amazingly comprehensive site covering Japan from prehistory to 1192. Don't miss this one!
From Hunters to Rice Growers テ Jomon Period -- http://www-history/pre-agri.html
Discusses the life of the Jomon people with graphics of and links to artefacts, with a focus on the diet, hunting methods, agriculture, and cooking methods.
Early Jomon Hamlet Found --
The Japan Times reports on the discoveries of Jomon culture artefacts on the island of Kyushu.
Japan Guide: Early Japan, until 710 --
About early Japanese history: Jomon, Yayoi, Kofun periods.
Introduces the Jomon, Yayoi, and Yamato cultures of Japan. (aka Schauwecker's Guide to Japan).
Oya Skeleton May be Jomon Period's Oldest --
The Japan Times reports the discovery of a Jomon skeleton that carbon dating indicates may be the oldest from the Jomon period.