You really shoudln't worry about any of those things - most people who venture out to Narita on a 7 hour transit don't speak any Japanese either. Most of the important signs (the ones you'd need to read to find your way about) are in English or bilingual. It really shouldn't be too much of a problem at all.

And having seen sumo wrestlers in action, and met with them, and stumbled upon them cycling around a neighbourhood, please don't even feel the least bit pre-occupied about being mistaken for one. These guys carry themselves with true dignity, are incredibly supple and amazingly athletic. Occasionally foreign sumo wrestlers (of all different abilities, male and female) visit Japan, from what I've seen they are treated with a little bit of interest (as a very large person might be everywhere) and with respect.

No need at all to carry those nightmares around with you - I'm sure you'll find Japanese srangers to be more polite and considerate than you would the people of almost any other country.

I really invite you to consider going landside for a little while and visiting Narita - the restaurants, ramen shops and tonkatsu joints are better and cheaper than those at Narita airport - the local streets are charming and atmospheric, and the temple and its grounds are quite beautiful.

De verdad, seguro que le trataran mucho mejor de lo que usted piensa. Pierda esas pesadillas!