I was having the same problem with unzipping it. After poking around the internet (cause I didn't want to switch any settings), I downloaded the latest winrar, went somewhere in the options (sorry, forget the exact spot), and was able to tell it to extract specifically Japanese unicode... think it was 192, but if you find where it is you should be able to figure out which one pretty easy
Then I deleted winrar cause I don't like it very much, but that worked for me
(Also saw something about maybe being able to do it on 7zip using console commands, but couldn't figure out how to access the console so gave up and did this option. Hopefully it helps anyone that's not keep on dealing with region setting stuff)