Your favourite city outside of Tokyo/Kyoto/Osaka?

Upcoming travel in December for two weeks, will be my second time and my partners first time.

We will be dedicating 8-9 days for the major cities Tokyo/Kyoto/Osaka, and 5-6 days to explore other cities.

Im tossing between exploring Kanto/Chubu Region or Kansai/Chugoku.

Nothing is set in stone, and Im open to suggestions of other must visit cities.
The below is what i have come across in my research

OPTION A:

Kanazawa, Takayama, Mt Fuji, Snow Monkeys, (unfortunately some of the alps attractions and kamikochi are likely closed in december)

OPTION B:

Kobe, Himeji, Hiroshima, Miyajima, Kinosaki Onsen

Edit – Thankyou for all your amazing recommendations!!