Does the Japanese language have analogues to the English words “sir” or “ma’am?” if not, how would one address an unfamiliar person?
In Japanese, when you’re greeting an unfamiliar person it’s based on gender and relative age. You address old women and men with “grandmother/grandfather”, slightly older with “aunt/uncle”, a tiny bit older with “big sister/brother” and younger with “little sister/brother.” I’m not sure about adults addressing small children, but that’s generally how I was taught in class to do it. I think it’s different if they have an obvious title, i.e. greeting a police officer I think that usually has its own titles like “officer” in English.
- Aunt and grandmother are very similar words, which leads to kindly old ladies jokingly correcting young people calling her “obaa-san” (grandmother) with “oba-san” (aunt) :).
How would a Japanese person write “To whom it may concern”? Assume they won’t know gender, age, or any other identifying characteristic.
There are no unfamiliar people. Real Japanese people exchange business cards upon first contact. 
For things like “to whom it may concern” you usually use some form of “person” plus an honorific and a descriptor (Japanese is agglutenative) –
関係者 kankeisha is something like “authorized person” or “persons concerned”
So “kankeisha no kata e” is “to any people who this concerns” (if you want to be really, stupidly literal, it’s like “in the direction of concerned persons”). I’ve never lived in Japan, but I’d suspect that if you’re addressing a group of people, you usually use some title, like “to people in the saitama prefecture” or “to the software department.”
There is, also, “anata” which means “you” but it’s very, very informal. I have heard “anata” used by pop or movie stars addressing the audience, but I doubt it’s used much in any formal context.
The family member thing is certainly done, but it’s an informal thing. Done when telling someone they’ve dropped their wallet, etc.
As in a formal letter opening? In Japanese you can refer to someone by their status, so there’d be nothing wrong with addressing it to “customer” or “company representative”, etc. There’s an opening that more or less literally means “to whom it may concern” that is commonly used (関係者各位), but only when a document is being sent to multiple people, not anyone in particular.
If you think this is weird, consider English,
“Dear valued/esteemed customer,”
Isn’t exactly an odd construction, pretty much the same is done in Japanese.
Ok, look. I want to say something to someone I don’t know, and do it politely. e.g. Someone I’ve never met before drops their wallet. Here I would say “Sir? You dropped your wallet.” how would I address such a person in Japanese, assuming they’re of similar age as me?
I would generally say “sumimasen” (excuse me). If I didn’t get his attention I’d say it again and tap him on the shoulder, hand him the wallet and say “saifu o otoshimashita” (you dropped your wallet).
My language bar isn’t installed on this computer, so I can’t do it in kana, but I’d probably go with something like
aaa… chotto, sumimasen, saifu ga taoremashita
Literally, “Excuse me, the wallet fell”
(or waretto)
If you want to be specific that it’s his:
aaa… chotto, sumimasen, onii-san* no saifu ga taoremashita
“Excuse me, your wallet fell”
- If you’re older, I looked it up and it’s not age-relative from what I thought, a “young man” is onii-san, an older man is oji-san
Japanese really isn’t big on ascribing “fault” when something happens. Things usually “happen” and it’s nobody’s fault. Further, the way its linguistics works, it often avoids referring to specific people unless it has to, you usually infer the subject, topic, and ownership by context. I’ve been told one easy way to differentiate a native speaker from a non-native one is whether or not they begin their sentences with a first person pronoun (native speakers don’t).
I know for a fact that you’re more qualified to answer this question than me, but I’ve been told both by native speakers and linguists that it’s more natural for a native speaker to avoid transitive verbs, and that the average Japanese person is more likely to say (for instance) “the vase broke” rather than “the cat broke the vase.”* I defer to your experience, and obviously there’s wiggle room (native speakers don’t all think alike), but it’s what I’ve heard.
- Which isn’t to say Japanese people are more or less likely to mentally decide whether something is or is not at fault, just that linguistically they’re more likely to say one than the other.
Forget I asked.
I don’t know what you want from us. Here’s the blunt answer to your question: no, Japanese does not have a good analogue to sir or ma’am. When you address an unfamiliar person, you either use their title, their familiar age honorific (onii-san etc), ask their name, or avoid the subject altogether. In cases where you address a group of people you use constructions like “to affected persons.”
If you work in a company, I believe there are general words for “superior” if you’re talking to your boss’ boss and you don’t exactly know their title, but there’s nothing generic like English’s “sir”. Or if there is, it’s such an uncommon usage there might as well not be.
Edit: And now you’ve learned why if there’s one thing in Japanese that’s a complete pain in the ass to learn, it’s the rules of social interaction. You don’t even WANT to get into all of the different ways to say “to give” or “to receive” depending on relative social standing. Learning about the social dynamics of a workplace is positively Lovecraftian.
For what it’s worth, denshi jisho lists “danna” as ‘sir’, but it’s not perfect, it’s usually only used to address customers or superiors at work.
You don’t have to worry about determining the correct honorific in such a situation. Just say ‘excuse me’ (in Japanese of course), followed by ‘is this your wallet?’, then say ‘you’re welcome’ after he thanks you. Done. There’s no need to complicate such an interaction, or stress yourself out about it. It’s just not important in that circumstance.
Sure, I’d agree with that (though in this case you’d use ochiru rather than taoreru).
I’d go so far as to say there is no polite honorific that can be used in such a situation. Using any honorific can be considered rude.
I always forget the distinction between those two, what was it again? Inanimate vs animate?
Taoreru means “fall over” rather than “fall”. Something that was standing no longer can. This can be a person, a building, a tree, etc.
Is there any relatively esay way to understand the usage of the suffixes used with names, like -san, -chan, and -sensei?