The ritual is performed biannually on June 30[2] and December 30[3] at several shrines, but also as necessary, such as after an offense is committed, at the Daijosai, or when an unmarried prince or princess departs the imperial palace to visit Ise Shrine or the Kamo Shrines.
[5] The primary theory is that the Ōharae-shiki began at the end of the seventh century.
These changes were linked to modifications to the Ritsuryō system, a set of laws and rules, in the eighth century.
[1] Purification became more important to prepare for this ritual and Yoori [ja] became more prominent in the Meiji restoration.
[4]: 362 [clarification needed] Though the Ōharae-shiki conducted in June is sometimes confused with the Minazuki-barae (水無月祓)—another purification rite that takes place at that time in the imperial court—they are conducted separately.