Most restrooms in Japan have the universal picture of the man or woman to help you find the right restroom. The other hint is that the men's restroom usually doesn't have a door and the urinals are directly across from the entrance. If you see men standing facing the wall and you're a woman, find the other restroom.
This is a subway restroom. The subways in Japan look a lot like the subways in London, Germany, and the U.S. The maps are designed the same way. Each line has it's own color etc. and the stops are listed on a map inside the car, usually above the door. As you can see the signs are very helpful when they include our alphabet (rumanji). You can count the stops from where you started and look for the rumanji lettering for your stop.
It's more difficult if you have to look for the kanji since that is not familiar to us. For example if it didn't say "toilet" on this sign, you would have to look for the combination of an unhappy face, a telephone pole with three lines, and a man with a hat running from a semicolon with a dot above it. That's a lot harder to recognize as your subway car sails past the sign. Karen said when they first arrived there were few rumaji signs, but in preparation for the World Expo in Nagoya this year, they put up a lot of new signs. Good thing because otherwise we wouldn't have known when we'd gotten to Nagoya. Even if you've figured out how to pronounce the name of the place you're going, it doesn't sound the same on the train or subway recording. The name melts into all the other words that come before and follow it.
People were very helpful to us when we were on public transportation or walking around trying to figure out where we were going. Somehow they recognized that we were tourists and that we probably spoke English...
Nighttime subway is quite different from daytime subway. Riders during the day are very quiet. If a cell phone rings, they move to the end of the car to talk quietly. Usually they text message each other on their cell phones or nap. No one even talks to the person sitting next to them. After dinner, however, the restraint disappears. One night we got into a car full of middle-aged (like us) dinner companions who were all laughing, teasing, and joking loudly across the aisle with each other. It was quite a contrast.