Japan trip in January

We will be visiting Japan in January (17-31). This will be our (couple) first trip to Japan and would like to hear any recommendations/tips/ etc to help plan our itinerary!

Thanks!

Edit:
There is a rough itinerary in my mind.
1. Land at Tokyo early morning on 17th Jan,
2. Travel to Osaka (flight or JR pass)
3. Stay in Osaka for 4 nights (plan to visit Kobe, Nara, Hiroshima and one day just to explore Osaka city?)
4. Go to Fukuoka on 21st. Stay for 3 days. Plan to explore nagasaki and kumamoto
5. Fukuoka to Kyoto (stay in Kyoto for 3 days 24-27)
6. Kyoto to Tokyo. Stay in Tokyo from 27-31
7. Fly out on 1st morning

I would like to get recommendations on things to do in each of these places (mix of typical touristy things and something new or local)

Kyoto seems really nice but would like to get your suggestion on whether I should reduce it to 2 days and increase a day in Tokyo.

Lastly, Tokyo seems overwhelming. Please suggest some good day trips and things to do in the city itself.

Thanks a ton! And apologies for the half arsed post previously🙏

by BallerGeek7