Japan: Can't take over Ainu Mosir

[Jyggalad]

Title. Fairly new to Victoria, so I'm unsure what I'm doing. I can't declare war on them, and I'm not sure what to do to make them part of Japan. Any guidance would be peachy

[Ixal]

Ainu Mosir is decentralized, so you must colonize them instead of attacking.

1, You must research colonialism (first thing you should do)
2. Pass a law that allows colonies. That is the hard part. The Samurai are for it but the powerful Shogunate does not care so its hard to get it enacted. Check which other faction supports it (I think Bourgeois) and bolster them and the Samurai.
3. Go to the diplomatic lense and colonize them. Right click on the state also works.

[Alehkra]

They're not a centralized nation, you can't declare war on them (though they can on you, in a way, tho personally I've only had a native uprising on Sakhalin). First you have to research Colonization, and then pass either the Colonial Settlement or Exploitation laws.

It'll piss of the peasants, they want to remain completely isolationist, but the Samurai endorse it so you should be able to pass it without too much trouble. Occasionally though the Shogunate's faction leader will have the Pacifist trait which can muck everything up, and is an...odd trait for the leader of a military government to have imo. I've been toying with the idea of making a proper Bakafu IG mod so they aren't just a Landowners localization (it also seems strange to me they prefer peasant militia over professional army)

[PurpleMonkeyDishWasher]

At the moment you have to be lucky. As stated above, bee line colonization and try to use the samurai to pass the new law. But of course in that time, Russia can already be in Hokkaido before step one is done. I had several playthroughs where I was too late, and one where I was lucky enough to take both Hokkaido and Sakhalin.

Honestly it's nice, but if you can't take Hokkaido in time don't despair. You can bid your time and build up your country till you're ready to smash the Russians.