"San"
"San (ãã ) is the most common honorific and is a title of respect. It is used for the surnames or given names of both males and females. Although in translation san is usually rendered as a common courtesy title like "Mr." or "Ms.", unlike these it is never used in self-reference. Using san to refer to oneself makes one appear childish or incredibly vain."
"San may also be used in combination with nouns describing the addressee or referent other than the person's name; for example, a bookseller might be addressed or referred to as honya-san ("bookstore" + san), and a butcher as nikuya-san ("butcher shop" + san)."
"San is also used when talking about companies and other similar entities. 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."
"Although, strictly speaking, not an honorific title in this usage, san can also be attached to the names of animals or even food products. 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 feminine or childish (akin to "Mr. Rabbit" in English) and would be avoided in formal speech."
"In western Japan (Kansai), particularly in the Kyoto area, Han (ã¯ã ?) is used instead of san."
"Online, Japanese gamers often append a numeral 3 to another player's name to denote san (e.g. yoshimitsu3 conveys yoshimitsu-san), since the number three in Japanese is pronounced "san"."
"Kun"
"Kun (ãã ) is an informal honorific primarily used towards males (it is still used towards females, but rarely). It is used by persons of senior status in addressing those of junior status, by males of roughly the same age and status when addressing each other, and by anyone in addressing male children. It can also be used by females when addressing a male that they are emotionally attached to. Usually it depends on the relationship between the two people. In business settings, women, particularly young women, may also be addressed as kun by older males of senior status. It is sometimes used towards male pets as well."
"School teachers typically address male students using kun, while female students are addressed as san or chan. The use of kun to address male children is similar to the use of san when addressing adults. In other words, not using kun would be considered rude in most situations, but, like the rule for using san in reference to family members, kun is traditionally not used when addressing or referring to one's own child (unless kun is part of a nickname: "Akira-kun"—Akkun)."
"In the Diet of Japan, diet members and ministers are called kun by the chairpersons. For example, Shinzo Abe is called "Abe ShinzÅ-kun". The only exception was that when Takako Doi was the chairperson of the lower house: she used the san title."