Black People of Japan...

The ancient Japanese (known as Jomon people), including Paleolithic Japanese, were East Asian, specifically a more basal branch of East Asians.

It is generally believed that the Jomon people were replaced by the Yayoi people who arrived in the Japanese islands sometime in the last 500 years BCE. By replaced, I mean the Jomon people were either pushed north to northern Honshu and Hokkaido and south to the Ryukyus and/or were assimilated by the Yayoi.