I've asked similar questions in the past about how to immerse in or at least experience in an authentic way, the indigenous cultures of the Australian aborigines and the New Zealand Maoris.
I've now been in Hokkaido (northern Japan) for a couple of weeks and when it comes to the indigenous Ainu people, have only seen a few nicknacks in odd places. I'm sure there are some museums and perhaps even some "Ainu World" type tourist traps. But what about for genuinely interested people who want to meet real Ainu who are proud of their culture and trying to keep it alive?
I have heard that the Ainu finally gained official recognition from the Japanese government as an indigenous people of Japan as recently as 2008. I'm wondering if there are some things that have come about since then?
I also just learned from a partial documentary on YouTube that many Ainu felt so repressed in Hokkaido that they moved to Tokyo. So perhaps it's just as likely that there is some contemporary Ainu cultural pride movement there that welcomes foreign visitors. It seemed to be hinted at in the video.
Finally, having languages and linguistics as a hobby, I'd be very interested to be able to visit any kind of Ainu language revitalization effort - I know there are only a tiny handful of fluent native speakers left.