Bogo no Mitchoku (a secret imperial decree) (戊午の密勅)
Bogo no mitchoku is an incident that Emperor Komei gave a chokusho (imperial decree) to the Mito Domain on September 14, 1858. "Bogo" is derived from Bogo (also called tsuchinoe, uma), the zodiac sign of that year when the chokusho was given, and "mitchoku" or a secret Imperial command means that the document was given without going through the official procedure which required to obtain approbation from Kanpaku (chief adviser to the Emperor), Hisatada KUJO.
The mitchoku was passed from Naofusa MADENOKOJI to Kichizaemon UGAI, the Kyoto rusuiyaku (a person representing the master during his absence) of the Mito Domain, and Kokichi UGAI, the son of Kichizaemon, passed it to Yoshiatsu TOKUGAWA, the lord of the Mito Domain, via Tatewaki AJIMA, Karo (chief retainer) of the Mito Domain. The mitchoku was conveyed to the Edo bakufu (Japanese feudal government headed by a shogun) through Ichio OKUBO, an assistant to Kinri (the Imperial Palace) several days later, but it was such a time-sensitive situations when the mitchoku was delivered to Mito earlier than to Edo. The mitchoku was kept secret from the Tokugawa gosanke and gosankyo (three privileged branches of Tokugawa family) other than the Mito Domain but the copies of it were sent to other related daimyo (Japanese feudal lord) through Sekke (line of regents and advisers) except Kanpaku.
Contents of the mitchoku
Condemnation against signing the Treaty of Amity and Commerce between the United States and Japan (five-parties treaty in the Ansei era) without an imperial sanction and demand a through explanation on it.
Order that the Tokugawa gosanke and other domains shall realize kobu-gattai, the union of the Imperial Court and the shogunate, in cooperation with the bakufu, and the bakufu shall accelerate to reform the shogunate government to promote the expulsion of foreigners.
The mitchoku had a rider which demanded to deliver the above two contents to other domains.
The contents of the mitchoku can be summarized as above. The fact that the chokusho was delivered directly from the Imperial Court to the Mito Domain that was regarded as a vassal of the bakufu meant that the bakufu was ignored and lost its dignity, so the bakufu kept the contents of the document confidential, which led to trigger the Ansei no Taigoku (suppression of extremists by the bakufu) by Naosuke II, Tairo (chief minister). Especcially, the letter from Kichizaemon UGAI to Tatewaki AJIMA was said that it contained the secret conspiracy to assassinate Naosuke II, and the leakage of its contents resulted in receiving stricter punishment in the Ansei no Taigoku.
Originally, since Nariaki TOKUGAWA had assumed the lord of the domain, the Tenguto (the Tengu faction) who were royal to Nariaki had been in fierce conflict with the Shoseito (the Shosei faction) who emphasized the relationship with the bakufu, and the feud between them were intencified over how to handle this mitchoku. Feudal retainers of the domain left the castle town and blocked roads and left the domain, and later organized an attack against Naosuke II.
Refer to the Sakuradamongai no Hen (The Incident Outside the Sakurada-mon Gate) and the Tenguto no Ran (Rebellion of the Tenguto).