Answer by Japanese teacher
When you do not know the other person’s name, ask for his/her name first and then address him/her using the “name + san” format.
(1) Sumimasen, onamae wa? すみません、お名前は
Excuse me, what’s your name?
Business setting and you do not know the other person’s name.
(1) Okyakusama お客様
(2) Sochirasama そちら様
Mr./Ms. That Person
“Anata” is indeed “you” but we cannot literally use “anata” as and when we like.
This is because the use of “anata” usually implies that you have a close relationship with the listener, usually that of a husband and wife, or boyfriend and girlfriend.
Depending on the context, it may also sound quite reprimanding, rude, or cold to the listener.
Therefore, Japanese people usually omit the use of “you”. However, this omission is quite difficult for English speakers because we tend to want to use “you”!
So what happens when we really want to say “you”? If you already know the listener’s name, you can say his/her name, followed by “san さん”. “San” can be translated as “Mr/Ms”.
It does not mean that we are acting polite and formal all of a sudden.
This “name + san” format is just a way to say “you”. Remember we are trying to avoid saying “anata” for the wrong reasons.
If you do not know the listener’s name or you may have simply forgotten it but you still need to address the person, ask for his/her name first. We can say “sumimasen, onamae wa” (Excuse me, what’s your name?) and then proceed to address him/her using “name + san” format.
If you are in a business setting and there’s no need for you to ask the other person’s name, you can simply address him/her by saying “Okyakusama” (Mr./Ms. Customer) or “Sochirasama” (Mr./Ms. That Person).
Remember that sometimes, we do not have to use the word “you” or the above alternatives at all. Word omission is quite common in the Japanese language, especially when the context is clear. You will be more adept at this if you practice more.