Oharae is an ancient Shinto purification ritual in which one-hundred court officials (including imperial princes) gathered in front of the Suzaku-mon Gate on the last day of the sixth and twelfth months of the year to cleanse people of their sins and purify them.
大祓（おおはらえ）とは、古来6月及び12月の晦日（つごもり）に、親王以下在京の百官を朱雀門の前に集めて、万民の罪や穢（けがれ）を祓った神事。