Rural Japan Forests outside of Tokyo or Osaka

hi,

when i will be in japan this summer for the 7th time, i really want to explore some rural sides with small train stations and access to the forests outside of tokyo or osaka.
can you recommend me some nice places?

thanks
marcel

Bessho Onsen would be my first pick (not that I have walked the trails there) - shinkansen to Ueda then nice little train ride to bessho Onsen, it has a really pretty little station. Karuizawa has a big station but a great foresty walk to the lookout which was part of the Nakasendo way

A place chosen as one of the top 100 forest bathing forests
https://mori-taki-nagisa.jp/pages/25/
Although I have never been there, Nishizawa Valley in Yamanashi Prefecture is one of the most famous.
About 1 hour by bus from Yamanashishi Station on the JR Chuo Main Line.
https://mori-taki-nagisa.jp/pages/65/
Tsugaru Juniko Natural Recreation Forest is a 15-minute bus ride from JR Juniko Station.
https://www.jalan.net/kankou/spt_02325ca3280123326/
http://www.shirakami-visitor.jp/
Neither seem to be able to walk in winter.

There are 1000s. If you be more specific in your wish-list. Eg time to go there, from where within Osaka/Tokyo. Alot more suggestions can be made.