Nope. As much as some Chinese (actually a lot of Chinese) enjoy parading our little fairy tales around that justify our superiority complex, Japanese didn’t start out from the 500 young boy and girls Xu Fu led on an oversea journey in searching of elixir of life.

There is evidence of human inhabitants as early as Paleolithic time period, long before Emperor Qin took power. Later on there's Jōmon period which was a hunter/gatherer culture. I have a hard time believe some hunter and gatherers from China decide it's a good idea to make a boat and sail to Japan during that time. Ci sono stati molti viaggi tra la Cina e il Giappone nel corso della storia (dopo l'invenzione delle barche...), e le nostre culture si sono influenzate a vicenda.

Ma la cultura giapponese non dovrebbe essere considerata una sottocultura, o un derivato della cultura cinese. Sono forse più una cultura fratello-sorella, che condivide molte cose in comune, ma ancora indipendente.