In Japanese culture, the honorific system acts as a pillar of social etiquette and respect. It is far more than a linguistic quirk - in fact it is a vital part of Japanese society. In the Japanese language, the main aim is not to efficiently get across information or instruction. Instead, it is to create harmony, or wa between the speaker and the listener. Therefore, the way in which one speaks is arguably more important than what one speaks about.
The system dates back many centuries, so it's difficult to pinpoint the exact point from which it originated. However, one thing that can't be understated is the impact of Chinese civilisation on the honorific system. In the 5th century, the Seventeen-Article Constitution was introduced, a document which outlined a code of ethics and principles for the Japanese court to follow. This constitution was heavily inspired by the introduction of Confucianism from China, which emphasised the importance of social hierarchy, respect for authority, and privileging elders. The system continued to develop in the Japanese court, to the point where using honorific language properly became vital for the court to function. Soon after, during the Heian Period (794-1185), the system spread from the Japanese court to the common people. In the Tokugawa Period (1600-1867), Japan adopted the foreign policy of isolationism, or sakoku, meaning that the honorific language used became increasingly more complex. Finally, after World War II, the entire system was simplified to the one used today.
The most commonly known aspect of the honorific system is the honorifics. These come after people's names and are used similarly to how one might use 'sir' or 'ma'am'. The most commonly used ones are below:
-San (さん) is one of the most regularly used honorifics. It's a neutral term that you'd normally use with someone whom you're not very familiar with, and is mostly like 'Mr/Ms'.
-Chan (ちゃん) is usually used with children, and sometimes close friends (normally women). It's the honorific which implies the most familiarity, and it comes from a childlike pronunciation of -San.
-Kun (くん) is often seen as a masculine suffix, used by young men and teenagers (who are familiar with each other) to address each other. However, it can also be used by a (normally older) person with higher social status talking to someone of lower status.
-Sama (さま) is seen as a more respectful version of -San. Its main applications are in business and clientele contexts. In Japanese culture, the implied social superiority of the customer or client is very strong, so this honorific is always used when addressing a customer as okyaku-sama where okyaku means customer. This suffix may also be used when addressing a group of people, where you might use mina-sama (mina: everyone) to express your respect for them.
Aside from honorifics, there are also two levels of speech: plain form and polite form, which can be identified by the verb, or lack thereof, used at the end of the sentence. The plain form is used when speaking with friends and family. This form conveys a sense of informality and is seen as much more natural and relaxed than the polite form. On the other hand, the polite form is used in formal settings, for example in a business setting or when speaking to someone of a higher social status. It can also be used when speaking with someone who you're not familiar with.
There are many other more complex linguistic nuances which relate to the Japanese honorific system. I believe that this is what makes Japanese such a unique but also difficult language, as in order to speak fluently, you have to not only learn the language, but also apply your own judgement of the situation in order to communicate appropriately. This kind of judgement is difficult to simply "learn" and can normally only be gained through experience of Japanese society.
Regarding the future, there appears to be some change on the horizon for the Japanese honorific system. Although the principles of harmony, social status, and respect are still deeply engrained in Japanese culture, both recent technological advancements and globalisation have changed the way that people interact and communicate. Therefore, an increase in more informal forms of communication and increased influence from other cultures will most likely cause some change to the system. However, I think that since the core values which the honorific system is based on are still crucial to Japanese society, the system will survive and continue to be used.
