Kin

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Kin, short for otherkin and fictionkin, also called "'kin" are people who identify as partially or entirely nonhuman or an entity from fiction. This identity is often involuntary.

Kintypes are not specific to plurality, as singlets can also be kin. However, there are some similarities between being kin and plurality, and system members can identify as both.

There are also similar related groups, such as therians or otherhearted.

Related Terms
A system that is composed primarily of kintypes can be described as a kin system.

A kinform is a kin that became a headmate.

Kins are not the same as fictives or extranths, but both do consider themselves to be nonhuman or fictional to some extent. People in a system can be kin and identify as kin for being fictive/extranth, but that does not mean being kin is inherently same as being an introject.