That's one theory. I prefer using the puppet nation of the Ainu Moshiri Republic, or the Hokkaido Republic if you will, from Fatcat's
JIS Project page.
Hokkaido has always been somewhat of a frontier area of Japan, as it's the largest prefecture in Japan but least densely populated. It's the homeland of the Ainu and has been the site of a seperatist movement during the Meiji when Tokagawa loyalists proclaimed the island's independence as the Republic of Ezo.
According to the JIS Project, Ainu and the other decendents of the Emishi, inspired by the Great Ghost Dance and the NAN, form an independence movement, fight JIS counterinsurgency forces in what is called the Donan War 2021-2022, and succed in seperating from the JIS. The JIS is too busy in the Phillipines to reinforce, so the JIS ends up negotiating with the Hokkaido Republic. The Hokkaido Republic establishes normal trade relations with the JIS through the Snow Star Corporation, who handle argiculture and the armed fishing fleets that scour the Okhotsk and the Aleutian seas. The Hokkaido Republic, backed by the JIS (and this is were I call them a puppet nation), also invade the Sakahlin islands and fight a border skirmish with the Russians in the Karafuto War. The Sakahlin islands evenutally are divided in half and maintained like Berlin following WW2.
Ainu Shamans would be relatively easy to run. They tend to trend toward animal and nature totems.
Remember, Ainu men have animal names and Ainu women have elemental names.