Japanese Honorifics

Chan
Chan is a diminutive suffix; it expresses that the speaker finds a person endearing. Thus, using chan with a superior's name would be condescending and rude. In general, chan is used for babies, young children, and teenage girls. It may also be used towards cute animals, lovers, close friends, or any youthful woman.
Although traditionally honorifics are not applied to oneself, some young women adopt the childish affectation of referring to themselves in the third person using chan. For example, a young woman named Kanako might call herself Kanako-chan rather than using a first person pronoun


Kun
Kun is used by persons of senior status in addressing or referring to those of junior status, or by anyone when addressing or referring to male children or male teenagers. It can also be used by females when addressing a male that they are emotionally attached to or have known for a long period of time. Although kun is generally used for boys, that isn't a hard rule. For example, in business settings, young female employees may also be addressed as kun by older males of senior status.


Sama
Sama is a markedly more respectful version of san. It is used mainly to refer to people much higher in rank than oneself, toward one's customers, and sometimes toward people one greatly admires. When used to refer to oneself, sama expresses extreme arrogance (or self-effacing irony), as with ore-sama ("my esteemed self").

Sama customarily follows the addressee's name on postal packages and letters and in business email.

Sama also appears in such set phrases as o-machidō sama ("sorry to keep you waiting"), o-tsukare sama (an expression of empathy for people who have been working long and hard), and go-kurō sama (an expression recognizing someone's labors), but although this is written with the same kanji, it is semantically distinct from the sama used as a term of address


San
San, sometimes pronounced han in the Kyoto area, is the most common honorific and is a title of respect similar to "Mr.", "Miss", "Mrs.", or "Ms." However, in addition to being used with people's names, it is also employed in a variety of other ways.

San is used in combination with workplace nouns, such that a bookseller might be addressed or referred to as honya-san ("bookstore" + san), and a butcher as nikuya-san ("butcher shop" + san).

San is sometimes used with company names. For example, the offices or shop of a company called Kojima Denki might be referred to as "Kojima Denki-san" by another nearby company. This may be seen on the small maps often used in phone books and business cards in Japan, where the names of surrounding companies are written using san.

San can also be attached to the names of animals or even inanimate objects. For example, a pet rabbit might be called usagi-san, and fish used for cooking can be referred to as sakana-san. Both uses would be considered childish (akin to "Mr. Rabbit" in English) and would be avoided in formal speech. It's also not uncommon even for married couples to refer to one another with san.


Senpai and kōhai
Senpai is used to address or refer to one's senior colleagues in a school, company, sports club, or other group. So at school, the students in higher grades than oneself are senpai. Students of the same or lower grade are not senpai, nor are teachers. In a business environment, colleagues with more experience are senpai, but one's boss is not a senpai. Like "Doctor" in English, senpai can be used by itself as well as with a name.

A kōhai is a junior, the reverse of senpai, but it is not normally used as an honorific.


Sensei
Sensei (literally meaning "former-born") is used to refer to or address teachers, doctors, politicians, and other authority figures. It is used to show respect to someone who has achieved a certain level of mastery in an art form or some other skill, and is also applied to novelists, poets, painters, and other artists, including manga artists. In Japanese martial arts, sensei typically refers to someone who is the head of a dojo. As with senpai, sensei can be used not only as a suffix, but also as a stand-alone title.

Sensei can be used fawningly, and it can also be employed sarcastically to ridicule such fawning. The Japanese media invoke it (rendered in katakana, akin to scare quotes or italics in English) to highlight the megalomania of those who allow themselves to be sycophantically addressed with the term.


Shi
Shi is used in formal writing, and sometimes in very formal speech, for referring to a person who is unfamiliar to the speaker, typically a person known through publications whom the speaker has never actually met. For example, the shi title is common in the speech of newsreaders. It is preferred in legal documents, academic journals, and certain other formal written styles. Once a person's name has been used with shi, the person can be referred to with shi alone, without the name, as long as there is only one person being referred to.