同士

同士 is a suffix used to describe relationships or actions within a group of people or things who share a common bond or context. It emphasizes mutuality, camaraderie, or interactions among members of the same group rather than individual actions. It’s often used after a noun to indicate “within/among the Xs” or to describe things done between members of the same group. It can pattern after groups like friends, colleagues, nations, teams, etc., and it can pair with verbs or adjectives to show mutual or shared activity or relationship.