The basic concept revolves around dividing people into in-groups and out-groups. When speaking with someone from an out-group, the out-group must be honored, and the in-group humbled. This is achieved with special features of the Japanese language, which conjugates verbs based on both tense and politeness. It may also include social concepts such as gift giving or serving. The uchi-soto relationship can lead to someone making great personal sacrifices to honor a visitor or other person in an out-group.
One of the complexities of the uchi-soto relationship lies in the fact that groups are not static; they may overlap and change over time and according to situation.
Uchi-soto groups may be conceptualized as a series of overlapping circles. One's position within the group, and relative to other groups, will depend on the context, situation and time of life. For example, a given person will usually have a family, a job, and other groups or organisations to which he or she belongs. His or her position within the various groups and in relation to other groups will change depending upon the position he or she is occupying at a given moment.
Thus, a company employee may occupy a superior position within the specific company, but a humble one in relation to the company's customers. The same employee may hold a black belt, giving him or her a superior position within his or her karate club, but may be a beginner at tennis and thus occupy an inferior position in the tennis club, and so on.
The workplace is a typical example: the employees below a middle manager are in his in-group, and may be spoken to using casual speech, while his bosses, or even, in large companies, people in other departments, are in an out-group, and must be spoken to politely. However, when dealing with someone from another company, one's own entire company is the in-group, and the other company the out-group. Thus, it is acceptable for the middle manager to speak of his own company, even the bosses, in non-honorific speech. This emphasizes that the company is one group, and although that group may have subdivisions inside of itself, it does not include the other company.
For example, when speaking with his subordinates a manager might omit the honorific -san, whereas he would be unlikely to do so when addressing his superiors. On the other hand, when dealing with an outsider—essentially any person not directly connected to the company—he would omit all honorifics when speaking about anyone in the company, including his superiors.
However, if the same manager speaks to a subordinate about his family, he will refer to the subordinate's family, which is the subordinate's in-group but not his, in polite terms, but his own family, which is his in-group but not the subordinate's, in plain language. Thus, the manager and the subordinate would both refer to their own families as kazoku (family) and to the other's family as go-kazoku (honorable family).
In addition to features of the Japanese language, uchi-soto also extends to social actions. For instance, in a Japanese home the most senior family member, usually the father or grandfather, normally takes a bath first; the rest of the family follows in order of seniority. A visitor to the home, however, would be offered the first bath. Similarly, an overnight guest would be offered the best sleeping arrangements, even if this would greatly inconvenience the rest of the family. This latter case is a difficult point for Westerners in Japan, who are usually taught to be polite by refusing accommodations that would inconvenience others.
Visitors and tourists are universally soto. As a "soto" group, they are treated with respect by the Japanese community.
"Soto" people (ex. foreigners, ethnic minorities) wishing to become "uchi" (i.e. Japanese citizens) face many obstacles. One must appropriate Japanese culture, including language (both indirect and direct forms), prioritizing group cohesion over individual inspirations, conforming to societal expections of one's role, accepting one's place in the country's social hierarchy, etc.
Theoretically, it is possible for a foreigner to become a part of Japanese society. However, in reality it is very difficult for non-Japanese to be accepted as an "uchi" member of Japanese society. In following Japanese customs of collectivism, deciding individually to become a part of a certain group does not mean that one actually is a part of that group. Naturalization does not guarantee inclusion in Japanese society; one must win the consent of the society at large.
For detailed information, see Honorific speech in Japanese.
Japanese honorific language ("keigo") is divided into three forms: polite, humble and respectful. Within these forms, there are specific words and prefixes.
For example, the verb "to eat" may be given as
and the noun "a drink" may be given as
Nouns involving the family, the household, or familial relations normally take honorific prefixes when denoting an out-group and not when denoting an in-group.
Some nouns change completely for the same reasons, such as chichi and haha ("my father", "my mother") versus o-tō-san and o-kā-san ("your father" and "your mother", and also used when addressing one's own parents respectfully).