Anyone visiting Japan for the first time will quickly realize that the shopping experience is something special. The retailers, shopkeepers and clerks are unfailingly polite and courteous. With the exception of formal or somber environments, the moment you step into a place of public accommodation you are greeted with enthusiastic cries of irashaimase, meaning, "welcome." Especially in a restaurant, where much of the staff will not see you immediately, the initial irashaimase starts a chain reaction of greetings that ripple across the establishment.
Keigo is the term for formal, polite Japanese. It is how you address your superiors at work and your doctor when you go for a checkup. It is also the default way to speak to any stranger. This goes double for guests. You'll receive so many bows and thank yous (arigatou gozaimase) that you will either be charmed or vaguely suspicious that you are being put on.
There is, however, a downside to the customer experience in Japan. When a situation is out of the ordinary, and requires -- to the American mind -- an exception, that flexibility will probably not be forthcoming. Say you want to check out of a hotel a few hours late because you have fallen ill. You'll likely be charged the normal late fee, regardless of the amount of time you have stayed and whether or not there is a pressing need to change out your room for a waiting customer. Substitutions in restaurants are rarely permitted. Partially, this is due to the corporatism of Japan. Most of the businesses you encounter are under a larger umbrella, and while the person you are dealing with may personally want to bend the rules, at the end of the day he or she would rather apologize to you than be chewed out by the boss. Also, even the Tokyo establishments that cater to an international crowd get a large portion of their business from the domestic market, and the Japanese customer rarely thinks that his/her situation, even if exceptional, warrants something outside of the normal code of conduct.
But within the lines of typical requests and inquiries you will be hard pressed to find better service than Japan's. A typical shopkeeper will answer all questions thoughtfully and patiently. He or she will not try and steer you out of your price range, and will tirelessly discuss and show different products and options. Above all, you will be left alone if you say that you are just looking or need to think.
Below is a photo album of some of the shopkeepers I dealt with while in Tokyo recently. I hope their commitment and professionalism comes through in the photographs.