Hello, Tumblr shown me a post of yours in a community I'm not part of, but if you're still considering visiting Tohoku/areas north of Tokyo, I can give you some suggestions, if you like! I used to live up there.
First, there's a JR Pass focused on northern Japan only, and imo it's more cost-effective than the all-around JR Pass. I'd definitely consider it if you plan to travel very far in the north, because the distances are pretty long in some cases. Also, you might be able to catch one of the tourism trains in the area (JR Joyful Trains, I think they're called)
Just off the top of my head, some popular places are...
In Tochigi Prefecture (not Tohoku, but north of Tokyo): Nikko World Heritage site (Tobu railways has a travel pass from Tokyo, I think), Tobu World Square,, Ashikaga Flower Park
In Niigata Prefecture (not technically Tohoku, but close enough, and accessible by Joetsu bullet train): Echigo-Yuzawa Onsen area, Echigo-Tsumari Art Triennale (maybe by bus tour, much easier) + Tunnel of Light, Ponshukan (sake sampling in certain bullet train stations, remi ds me of Baskin-Robbins), Northern Culture Museum...
In Fukushima (they spent 10 years working hard to clean up after the nuclear meltdown, and only the area nearest the reactors is now closed - they have solar-powered Geiger counters here and there, I think, if you wanted to check...): Spa Resort Hawaiian, Aizu-Wakamatsu (samurai school Nisshinkan, former samurai home Bukeyashiki, castle), Kitakata (ramen), Ouchijuku (bit like Shirakawago), Soma (more samurai culture, +horses), Urabandai (outdoor activities), Oze National Park (nature)...
In Yamagata: Ginzan Onsen, Mt. Zao, Yamadera mountain temple
In Akita: Kakunodate (samurai neighborhood + homes, sakura spot)
In Iwate: Morioka (wanko soba, reimen - not ramen - noodles), Sanriku coast (nature, memorials & museums about the 2011 tsunami)
In Miyagi: Sendai, Matsushima Bay (nature), Naruko Gorge (autumn color spot)
In Aomori: Nebuta Wa-Rasse museum (for cool local festival floats), Hachinohe (morning market, also has a cool local festival) + Tanesashi Coast, Hirosaki (castle, samurai culture), nature & resorts around Lake Towada, delicious apple & seafood products...
I've barely visited Tochigi, Iwate, Akita, and Miyagi, and I haven't been to Yamagata at all, so I'm sure I've missed some things
the much needed details, I am almost lost with where and what to look out for Autumn but thanks for the respective areas and what to look out for. I am not sure about going to Fukushima, because of all the tsunami videos i've watched despite it happening 11 years ago. But you know what I might look into it more. Thank you so much for the information I really appreciate it