OK thanks a lot guys! Actually the suitcase is maybe a bit bigger than normal sized. But when I board the Shinkansen I'll try to find a place to put it hehe, usually what times are the less-crowded?
I read about the JR rail pass, I didn't know that it existed hehe so I'll try to buy it before going to Japan, I want to visit tokyo, nagoya, osaka, kyoto, and maybe other city, I was planning on travel a whole week or two weeks around japan, if I want to visit more cities with the all-japan JR rail pass will be no problem right?