Japanese people’s suitcases

Hi,
Odd question maybe but I keep wonderin what the most common size of the suitcases japanese people use when travelling domestically.

Since there are limited spaces on most trains I suppose they are not really big. I remember seeing really small ones, but maybe they are not away for more than a few days with that size? Or maybe they use takkyubin service or other service for the bigger lugguage?

Most people travel domestically with a carry-on size or smaller. The typically traveller should be able to take enough stuff in that size luggage for around a week, while seasoned travellers could go indefinitely.

In the past (well, 30 odd years ago), when the international travels are not so common among Japanese people, suitcase (hard case) is only for international travel, so most of Japanese did not have it. When we had a chance to travel abroad, we bought suitcase and use it for international travel. Someone then were using it for domestic travel, but others preferred travel bag for 3 days (or so) of clothes. If you do not stick to your own cosmetics/toiletries, most hotels provide them and you can omit them from your belongings. I personally choose my 25L backpack for domestic travel (I am a 60 years old Japanese male) though I must say I am not a fashionable person. When traveling abroad, I will add a carry-on size suitcase because I may want to bring something which are not allowed to bring into the airplane and I am afraid that my luggage might lost during the flight process (I experienced twice). Usually I check in my suitcase and carry on my backpack.

I am always wondering about the big suitcase foreign travelers (and Japanese travelers going abroad) carrying. Do they have several sets of suit in it?