Assistance/Help button: Subway ticket machine
Tokyo is covered by a dense network of train, subway and bus lines. They are operated by about a dozen different companies. The train lines operated by JR East and the subway lines are most convenient for moving around central Tokyo. Although smartphones and mobile phones can provide great navigation these days, it can be sometimes difficult to move around even for me, Japanese. I could easily image how difficult it could be for overseas tourists.
So, I would like to share this Youtube movie here to set your mind at ease a little bit. You should know this awesome customer service! It's pretty common in almost all Japanese Railway stations. :-)