The was a successful plot by Nakatomi no Kamatari (Fujiwara no Kamatari), Prince Naka no à Âe and others who conspired to eliminate the main branch of the Soga clan, beginning with the assassination of Soga no Iruka. It takes its name from the zodiological name of the year 645 during which the Taika Reform, a transformative event in Japanese Imperial history, occurred.
The assassination of Iruka took place on July 10, 645 (traditional Japanese date: 12th day of the 6th month of 645), during a court ceremony at which memorials from the Three Kingdoms of Korea were being read to Empress Kà Âgyoku by Ishikawa no Maro. Prince Naka no à Âe had made elaborate preparations, including closing the palace gates, bribing several palace guards, hiding a spear in the hall where the ceremony was to take place and ordering four armed men to attack Iruka. However, when it became clear that the four men were too frightened to carry out the orders, Naka no à Âe rushed Iruka himself and cut open his head and shoulder. Iruka was not killed immediately, but protested his innocence and pleaded for an investigation.
Prince Naka no à Âe pleaded his case before Empress Kà Âgyoku, and when she retired to consider the matter, the four guards finally rushed Iruka and completed the killing. Shortly afterwards, Iruka's father Soga no Emishi killed himself by setting fire to his residence. The conflagration destroyed the manuscript copy of the Tennà Âki and many other Imperial treasures which had been taken for safe-keeping by the Soga, but Fune no Fubitoesaka quickly grabbed the burning Kokki from the flames. Later, he is said to have presented it to Naka no à Âe; but no known extant copies of the work remain.
The violence actually unfolded in Kà Âgyoku's presence. The Empress responded to this shock by determining to renounce the throne. Japanese society during the Asuka period was sensitive to issues of "pollution", both spiritual and personal. DeathsâÂÂespecially a violent killing in close physical proximity to the EmpressâÂÂwere considered to have been amongst the worst possible acts of pollutionâÂÂan event so stunning that it would have warranted days of seclusion in an uncertain process attempting to redress what would have been construed as a kind of profanity.
Although Kà Âgyoku wanted to abdicate immediately in favour of Naka no à Âe, on the advice of Nakatomi no Kamatari he insisted that the throne should pass instead to his older brother, Furuhito no à Âe, or to his maternal uncle (Kà Âgyoku's brother) Prince Karu. Furuhito no à Âe resolved the impasse by declaring his intention to renounce any claim to the throne by taking the tonsure of a Buddhist monk. That same dayâÂÂtraditionally said to be July 12, 645, Furuhito no à Âe shaved off his hair at Hà Âkà Â-ji, in the open air between the Hall of the Buddha and the pagoda. At this point, Kà Âgyoku did abdicate in favor of her brother, who shortly thereafter acceded to the throne as Emperor Kà Âtoku (645âÂÂ654). After Kà Âtoku's death Kà Âgyoku took the throne once more as Saimei (r. 655âÂÂ661), before Naka no à Âe himself finally took the throne as Emperor Tenji (661âÂÂ672).
Within the Nihon Shoki, a passage is found where rushes in to report the death of Soga no Iruka exclaiming:
Though the incident took place during a court ceremony for the envoys from Korea, scholars remain puzzled as to the meaning behind Soga no Iruka being "killed by a Korean". This prompted many Japanese historians to examine the exact meaning behind his statement, leading to several theories.
Despite much effort, the true meaning behind this passage remains unclear.