Groups are, of course, extremely important to human beings, since you can’t have much of a society without them. The various customs the Japanese have evolved regarding groups, such as having different categories of polite language for use when talking to someone from outside your company (soto) compared with someone from inside (uchi), or the inability to bring any group together without deciding who the leader will be (who then goes by titles like dancho, group leader, or kaicho, chairman), can really look odd to foreigners. While most people have different circles of friends they don’t bring together — I certainly wouldn’t expect the local Miata Club members to mingle well with my anime friends — the Japanese have raised this separation of different groups of friends to an art form. Because compulsory education ends with Junior High in Japan, most people have two groups of school-era friends: the ones that live in their part of town, who they went to the local Elementary and Junior High with, and a separate group of friends from High School, which is often located in another city. The idea of mixing these two groups together is almost taboo, since each group represents a separate set of experiences and memories that are walled off from each other, and going to dinner with friends from two different groups would be an extremely difficult situation for everyone.
