I live in Japan and I'm 90% sure it's just Tohouku (North Japan) in general, but mostly Aomori and Akita prefectures. Aomori is famous for apples. Literally every cafe has their own apple themed food there, and it's a local specialty.
I think Akita too because while all of Japan has stories of Oni, Akita has a famous story of an Oni that comes from the mountains and steals bad children.
https://www.tofugu.com/japan/namahage/Also "Kita" is literally just North in Japanese.