Luggage Recommendation – Suitcase or Backpack

Hi all,

Looking to get some recommendations from people who have travelled to Japan, and the type of luggage taken.

For context, I will be taking a 3-week trip at the end of the year, with a lot of movement between cities/towns, all of this done via train. I'm looking into the options between luggage types and am stuck between a rolling suitcase, or a backpack to carry. As a short woman, ease of movement and comfort re my two biggest requirements.

I'm leaning towards a backpack, specifically something that opens in a suitcase style like the Baboon To The Moon Go Bags rather than a top opener.

All recommendations, as well as any travel tips are welcome and appreciated!