A za did za-yaku (duties imposed on a za) or offered services to a court noble, a temple or a shrine which was their honjo (a controller and protector of a za), and in exchange for it the honjo granted some status such as Kugonin (purveyors to the Imperial Household), Yoriudo (dependents of powerful nobles, temples or shrines), or Jinin (associates of Shinto shrines) to za-shu (members of a za) of that za.
座は公家や寺社を本所として座役を納め、あるいは奉仕を行い、本所は座の構成員である座衆に供御人・寄人・神人などの身分を与えてこれを保護した。