To speak about tokyo : faily manageable. Prepare yourself before by checking internet sites
- look at the Tokyo railway map
- learn about the tickets
- learn even about the vending machines
When you are there, you will find it easy because all stations are written in English. Everywhere you will find railway officials who are eager to help you. English will be sufficient.
When i was in Tokyo 2 years before I used Suica prepaid card... Very handy to hop on and off the trains. about 9 years ago
I agree. However the Tokyo subway system is vast and be careful in the mega-stations like Tokyo and Shinjuku as the are truly huge with many exits (last time I was there it took us half an hour just to find the right way out of Tokyo station).
Oh, and unless you are in it for the unique experience, avoid the rush hour! almost 10 years ago