I asked some of my colleagues at lunch the other day what is the nature of the holiday coming up on Friday; I knew it was a national holiday, something like a founding of the nation. Someone said, "It's like independence day" to which I asked "Independence from whom? Japan has never been part of another country." I was careful not to say had never been occupied, because Japan was occupied by the U.S. after WWII. Nevertheless, someone answered "except America."
I'd been told before [actually by my friend Jim H., who has spent a lot of time in Japan], not to ask Japanese about their traditions, etc., because they don't tend to know or pay attention [such as differences between Buddhist and Shinto traditions]... so I went to Japan-guide.com, a great resource [from which I also just learned some chopsticks etiquette I should have already learned but haven't -- because chopsticks are used in some funeral rites] [and I also learned that women give chocolate to men on 14 February, good thing I looked!]
It turns out the foundation for Japan's National Foundation Day lies deep in the past:
February 11 is Japan’s National Foundation Day (kenkoku kinenbi):
According to the earliest Japanese history records, on this day in the year 660 BC the first Japanese emperor was crowned.
From the same website: According to mythology, Japan's first Emperor Jimmu, a descendant of the Sun Goddess Amaterasu, was enthroned in the year 660 BC. While the myths are not considered historically accurate, it is a commonly accepted fact that emperors have reigned over Japan for more than 1500 years, and that they have all descended from the same imperial family.
History of Early Japan (until AD 710) http://www.japan-guide.com/e/e2131.html
During the Jomon Period (13000 BC to 300 BC), the inhabitants of the Japanese islands were gatherers, fishers and hunters. Jomon is the name of the era's pottery.[note from Jody -- the origin of Foundation Day falls within the end of this period]
During the Yayoi Period (300 BC to 300 AD), the rice culture was imported into Japan around 100 BC. With the introduction of agriculture, social classes started to evolve, and parts of the country began to unite under powerful land owners. Chinese travellers during the Han and Wei dynasties reported that a queen called Himiko (or Pimiku) reigned over Japan at that time. The Yayoi period brought also the introduction of iron and other modern ideas from Korea into Japan. Again, its pottery gave the period its name.
By the beginning of the Kofun Period (AD 300 - 538), a center of power had developed in the fertile Kinai plain, and by about 400 AD the country was united as Yamato Japan with its political center in and around the province of Yamato (about today's Nara Prefecture). The period's name comes from the large tombs (kofun) that were built for the political leaders of that era. Yamato Japan extended from Kyushu to the Kinai plain, but did not yet include the Kanto, Tohoku and Hokkaido.
The emperor was ruler of Yamato Japan and resided in a capital that was moved frequently from one city to another. However, the Soga clan soon took over the actual political power, resulting in the fact that most of the emperors only acted as the symbol of the state and performed Shinto rituals.
Due to friendly relations to the kingdom of Kudara (or Paikche) on the Korean peninsula, the influence from the mainland increased strongly. Buddhism was introduced to Japan in the year 538 or 552 and was promoted by the ruling class. Prince Shotoku is said to have played an especially important role in promoting Chinese ideas. He also wrote the Constitution of Seventeen Articles about moral and political principles. Also the theories of Confucianism and Taoism, as well as the Chinese writing system were introduced to Japan during the Yamato period.
In 645, Nakatomi no Kamatari started the era of the Fujiwara clan that was to last until the rise of the military class (samurai) in the 11th century. In the same year, the Taika reforms were realized: A new government and administrative system was established after the Chinese model. All land was bought by the state and redistributed equally among the farmers in a large land reform in order to introduce the new tax system that was also adopted from China.