What sort of backpack/ luggage should I use for a 3 week trip to Japan?

Question

I will be in Japan this December, starting in Tokyo and more than likely traveling to a few other cities. I want to pack as light as possible to avoid having to cart big luggage with me onto trains and subways. Thanks in advance.

Answer 1

I'm having the same trouble I'll be going to Germany for 3 weeks in July.  I might just get a medium sized suitcase with a backpack.