The Ainu in Japan were only recognized as indigenous in 2008. Back in the 17th century they were essentially enslaved by the Japanese government. The government banned the Ainu language, forced them to take Japanese names and encouraged them to marry Japanese people in order to assimilate them into society. They were further prohibited from observing their daily customs and instead forced to abide by Japanese customs alone. In fact, in 1899 they were granted Japanese citizenship; not as a benefit, but as a way of keeping them from being recognized as indigenous.
As you can see from these Wikipedia images, the Ainu look nothing like the Japanese of today. They were and are an ethically different people group.
Despite everything, the 2008 declaration by the Japanese government acknowledged their past mistakes, stating, “The government would like to solemnly accept the historical fact that many Ainu were discriminated against and forced into poverty with the advancement of modernization, despite being legally equal to (Japanese) people.” Below is a video provided by the Ainu museum of women performing traditional Ainu dances. You can find more information at the museum website here: