san さん - Honorific

In Japanese, san さん is a honorific suffix, or the number "three," san 三.

The san さん honorific is the most neutral and common of all honorific suffixes. In modern Japan, it's normal to call someone by adding san さん after their names. For example: Tarou-san 太郎さん. In English, this is often translated as "Mr." or "Ms.," like Mr. Tarou.

• Usage
  
  • Internet Usernames
• San Juu

Usage

The san さん honorific is gender neutral, can be used toward men or women, people younger or older, people you know or that you don't, strangers, friends, family, colleagues, everybody, basically.

There are reasons to not use the san さん honorific. For example, some people find it weird to use san さん toward little children, and may use kun くん or chan ちゃん instead. Parents may use no honorific at all toward their own children.

Toward customers, in the business world, sama 様 is generally used instead.

Since you're normally used to use san さん toward other people, not using san さん, and calling them by their bare name, is considered informal, which means either being friendly, or overly intimate and rude, impolite.

Internet Usernames

Around the Japanese internet, it's normal for usernames to be suffixed with san さん automatically.

For example, if you create an account with the username xXNoobSlayer69Xx, your posts may have end up like this:

• xXNoobSlayer69Xxさん
  git gud lol

San Juu

There's a certain pun involving the san さん honorific when it's used to say somebody's age. That's because san さん also means "three," so you can end up with a situation like this:

• maria-san juu nana sai
  マリアさん１７歳
  Maria-san, 17 years old.
  • juu 十
    Ten. 10.
  • nana 七
    Seven. 7.
  • 10 + 7 = 17.
• maria san juu nana sai
  マリアさんじゅうなな歳
  Maria, 37 years old.
  • san-juu 三十
    Three tens. Thirty. 30.
  • 3 × 10 + 7 = 37.

Maria, in this case, is from Hayate no Gotoku! ハヤテのごとく！