Since the period of the Northern and Southern Courts (Japan), Kugonin had obtained the exclusive sales rights of the presents and conducted activities similar to those of Za, however, they lost their holiness with the loss of the dignity of the Imperial Family, which was the source of their privileges, some of them succeeded as large-scale merchants, and it is disputed that they were the origin of buraku one of the origins of the discriminated people.
南北朝時代(日本)以降は、貢納品の独占販売権を取得し座と同様の活動を行ったが、その特権の源泉であった天皇家の権威喪失とともに聖性を失い、一部には大商人として成功する者が出た反面、被差別民の起源のひとつともなったとする部落の起源論争もある。