Uchi–soto is the distinction between and . This distinction between groups is a fundamental part of Japanese social custom and sociolinguistics and is even directly reflected in the Japanese language itself. 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. That 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 depends on the context, situation, and time of life. For example, a person usually has a family, a job, and other groups or organizations to which they belong. Their position within the various groups and in relation to other groups changes according to circumstances 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 them a superior position within a karate club but may be a beginner at tennis and thus occupy an inferior position in the tennis club. 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. 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, the middle manager's entire company is the in-group, and the other company is the out-group. Thus, it is acceptable for the middle manager to speak about his own company, even his bosses, in non-honorific speech. That emphasizes that his company is one group, and although the group may have subdivisions inside of itself, it does not include the other company. For example, when speaking with subordinates, a manager might omit the honorific -san, but he would be unlikely to do so when addressing