O__san お〇〇さん

kyaku 客, "customer," and prefixing it with a chan, san, or sama, and maybe a o or go, turning the noun into a more honorific version of itself: okyakusan お客さん.

Why It Happens

In Japanese, it's considered rude to refer to people without honorifics sometimes, so to avoid sounding rude, people tend to add honorifics when using nouns that refer to other people.

Normally, this would happen when referring to people by name. For example, say someone is called Tanaka, you'd refer to them as Tanaka-san. However, there are some cases you don't know the person's name and yet you have to refer to them.

For example, you don't automatically know the name of every customer that enters the shop. They're "customers," kyaku 客, but referring to them as that can be considered rude, so to avoid pissing off your customer, you call them okyakusan お客さん instead.

What's considered rude or not varies. You can technically affix the honorifics to basically any word, but people don't do that, so at most only a handful of words get honorifics. Depending on the person, the word, and the context, formal or casual, written, etc. certain words may or may not get the honorific.

Also, there are cases where honorific speech is used because it's prettier, and in a sense, cuter, than normal speech. For example, a gang member may shout keisatsu da! 警察だ！ "it's da police!" but a mother walking around with her daughter may refer to the same people as omawarisan お巡りさん, "police officer."

Asymmetry in Family

In families it's common to have otousan お父さん, "father," and oniisan お兄さん, "older brother" used with honorifics, however, musuko 息子, "son," and otouto 弟, "younger brother," are usually without honorific.

This probably happens because of seniority. It's tradition that you have to respect your elders, so your parents, ancestors and older siblings get honorifics, but the opposite doesn't happen, at least not with the same frequency.

A special case is when talking about other people's families. For example, musukosan 息子さん normally refers to someone else's "son," and otoutousan 弟さん to someone else's "younger brother."

Examples

Here are some examples of o__san words.

Family

oniisan お兄さん
Older brother.
Pal. Guy. (colloquial, used toward strangers.)

otoutosan 弟さん
Someone else's younger brother.

oneesan お姉さん
Older sister.
Girl. Gal. (colloquial, used toward strangers.)

imoutosan 妹さん
Someone else's younger sister.

otousan お父さん
Father.

okaasan お母さん
Mother.

ojiisan お爺さん
Grandfather.

ojisan 叔父さん
Uncle.

obaasan お祖母さん
Grandmother.

obasan 叔母さん
Aunt.

okosan お子さん
Someone's child.

oyomesan お嫁さん
Bride.

goshujinsan ご主人さん
Husband.
Lord of the house. Master. (of a servant, maid, slave, common in anime, goshujinsama.)

ojousan お嬢さん
Someone's daughter.
Rich girl. (colloquial, ojouchan.)

obousan お坊さん
Someone's son.
Rich boy. (colloquial, obouchan.)

Professions

omawarisan お巡りさん
Police officer.
(goes on a "patrol in rounds," omawari お巡り, by "turning around," mawaru 回る)

oishasan お医者さん
Doctor.

otetsudaisan お手伝いさん
Maid. (the housemaid kind, not the moe french maid kind.)
(form tetsudau 手伝う, "to help (with something).")

Other

otonarisan お隣さん
Neighbor.
(from tonari 隣, "(something which is) next to (something else).")

oeraisan お偉いさん
Someone who's important, rich, powerful, etc.
(from erai 偉い, to be "important," "powerful," etc.)

osharesan お洒落さん
Someone who dresses up well.
(from share 洒落, "fashionable.")

obakasan お馬鹿さん
Someone who's silly.
(from

odebusan おデブさん
Someone who's fat.
(from debu デブ, which means fat.)

okamasan おかまさん
Someone who's an .

omaesan お前さん
You.
(from
(from mae 前, which means "front" of something. Historically, omae was the front of someone important, because referring to them directly was too rude, so they referred to the space in their front instead. The word has since then changed strongly in nuance.)

In Japanese, there's a practice of using a noun that describes people, like客, "customer," and prefixing it with a honorific suffix like, or, and maybe a honorific prefix like thator, turning the noun into a more honorific version of itself:お客さん.In Japanese, it's considered rude to refer to people without honorifics sometimes, so, people tend to add honorifics when using nouns that refer to other people.Normally, this would happen when referring to people by name. For example, say someone is called, you'd refer to them as. However, there are some cases you don't know the person's name and yet you have to refer to them.For example, you don't automatically know the name of every customer that enters the shop. They're "customers,"客, but referring to them as that can be considered rude, so to avoid pissing off your customer, you call themお客さん instead.What's considered rude or not varies. You can technically affix the honorifics to basically any word, but people don't do that, so at most only a handful of words get honorifics. Depending on the person, the word, and the context, formal or casual, written, etc. certain words may or may not get the honorific.Also, there are cases where honorific speech is used because it's prettier, and in a sense, cuter, than normal speech. For example, a gang member may shout警察だ！ "it's da police!" but a mother walking around with her daughter may refer to the same people asお巡りさん, "police officer."In families it's common to haveお父さん, "father," andお兄さん, "older brother" used with honorifics, however,息子, "son," and弟, "younger brother," are usually without honorific.This probably happens because of seniority. It's tradition that you have to respect your elders, so your parents, ancestors and older siblings get honorifics, but the opposite doesn't happen, at least not with the same frequency.A special case is when talking about other people's families. For example,息子さん normally refers to someone else's "son," and弟さん to someone else's "younger brother."Here are some examples ofwords.お兄さんOlder brother.Pal. Guy. (colloquial, used toward strangers.)弟さんSomeone else's younger brother.お姉さんOlder sister.Girl. Gal. (colloquial, used toward strangers.)妹さんSomeone else's younger sister.お父さんFather.お母さんMother.お爺さんGrandfather.叔父さんUncle.お祖母さんGrandmother.叔母さんAunt.お子さんSomeone's child.お嫁さんBride.ご主人さんHusband.Lord of the house. Master. (of a servant, maid, slave, common in anime,.)お嬢さんSomeone's daughter.Rich girl. (colloquial,.)お坊さんSomeone's son.Rich boy. (colloquial,.)お巡りさんPolice officer.(goes on a "patrol in rounds,"お巡り, by "turning around,"回る)お医者さんDoctor.お手伝いさんMaid. (the housemaid kind, not thefrench maid kind.)(form手伝う, "to help (with something).")お隣さんNeighbor.(from隣, "(something which is) next to (something else).")お偉いさんSomeone who's important, rich, powerful, etc.(from偉い, to be "important," "powerful," etc.)お洒落さんSomeone who dresses up well.(from洒落, "fashionable.")お馬鹿さんSomeone who's silly.(from baka 馬鹿 , "stupid.")おデブさんSomeone who's fat.(fromデブ, which means fat.)おかまさんSomeone who's anお前さんYou.(from omae お前 , which means, well, "you.")(from前, which means "front" of something. Historically,was the front of someone important, because referring to them directly was too rude, so they referred to the space in their front instead. The word has since then changed strongly in nuance.)