Tomei (Tang name) (唐名)

Tang names (tomei, tomyo, or karana) are Chinese names of government posts or departments each of which corresponds to a Japanese name of a government post or department whose official duties were similar to those of Tang under the ritsuryo system (a system of centralized government based on the ritsuryo code) in Japan.

In the early eighth century, in accordance with Taiho Ritsuryo Code and Yoro Ritsuryo Code, the office organizations, as described below, after the establishment of the government-regulated ritsuryo system (Taiho Ritsuryo Code), were developed and official titles of all the officials were established. Around that time, Tang-style official titles and department names representing the same official duties were already used as a kind of elegant name, and when FUJIWARA no Nakamaro, who idolized the Tang culture, took control of the government, the titles of all the officials were translated into Tang names in 758.
(Nakamaro himself had taken the title Shibirei [director general of Shibi institution] of the newly created Shibi chudai [office handling the principal empress Komyo's affairs], namely kotaigogushoku [Imperial Household Agency officer assigned to the household of Queen Mother])
After Nakamaro fell from the position in 764, the titles were returned to the former names, however, the Tang name was often used as another name or an elegant name of the government post. Various Ryoge no kan (posts outside the original Ritsuryo code created by Imperial edicts), which were created from the late Nara period to the Heian period, had Tang names.
(The Emperor Saga who set the posts of Ryoge no kan such as Kurodo no to [Head Chamberlain] and kebiishi [officials with judicial and police powers] also idolized the Tang culture.)

These Tang names do not completely match the office organizations originated in Chinese successive dynasties, so that they cannot be always replaced by one-to-one correspondence. Therefore, some organizations overlapped in using the Tang name; to the contrary, there were many cases in which a single organization had multiple Tang names.

Tang name was not used in a formal Iki (a letter of appointment) in Jimoku (ceremony for appointing officials) of Chotei (Imperial Court) and the like, however, often used in private documents such as letters, diaries, and Chinese-style poems. In the Edo period, Tang name was still continued as the elegant name attached to the Buke-kani (official court titles for samurai), and even after the ritsuryo system came to the end both in name and in reality by the Meiji restoration, it was taken over by attaching to the System of Departments of State in the early Meiji era.

In 1885, the cabinet system was established, and even in this system, the tradition of Tang name was taken over, so that the prime minister was called 'shusho' and the foreign minister was called 'gaisho.'
Further, the Privy Council which was established together with the cabinet system was called 'sufu', the Chairman of the Privy Council was called 'susho', and both the Office of minister of the center and the minister of the center were called 'naifu', thus, this custom has been completely established in Japan.

Examples of historic terms fixed by Tang name
SUGAWARA no MichizaneSUGAWARA no Michizane, the Udaijin (minister of the right.)
The name used in "Sugawara Denju Tenarai Kagami" (Sugawara's secrets of calligraphy), the masterpiece of Joruri (Ballad drama) and Kabuki (traditional drama performed by male actors).

Ribu O ki (diary of Shikibu-kyo) … The diary of Imperial Prince Shigeakira who was the prince of the Emperor Daigo.
The term comes from Shikibukyo of kyokkan (the most highest rank which one was appointed.)

Sankaiki … The diary of FUJIWARA no Tadachika (Nakayama Naidaijin [Nakayama, the minister of the center.])
The term comes from 'san' (=yama) in 'NAKAYAMA' and a different name of the minister 'Kaimon.'

FUJIWARA no YorinagaFUJIWARA no Yorinaga, the Sadaijin (Minister of the left) who was told as the ringleader of Hogen War.
Also called Uji Aku-safu (evil minister of the left.)

TAIRA no Kiyomori (nyudo-shokoku [the Grand Minister who became a priest]) … TAIRA no Kiyomori who became Daijo-daijin (Grand Minister.)

Heiko-ki … The diary written by TAIRA no Tsunetaka, the Minbukyo
The term comes from Minbukyo = Ministry of Revenue.

Choshuki (diary of MINAMOTO no Morotoki) … The diary of MINAMOTO no Morotoki. The term comes from Morotoki who served as Kogogushiki (the Queen-consort's Household Agency).

The Urin family … one of the ranks of kuge (a Court noble.)
The term comes from the government post of Konoe no shosho (Minor Captain of the Palace Guards) and Chujo (Middle Captain) as its Kashoku (one's trade or profession).

Hosokawa Keicho family … The main line of the Hosokawa family which produced many Muromachi bakufu kanrei (A shogunal deputy for the Muromachi bakufu.)
The term comes from kanto (government service) of Ukyo no daibu (Master of the Western Capital Offices.)

The Shiba clan Buei family … The main line of the Shiba clan which produced many Muromachi bakufu kanrei. The term comes from kanto of the Captain of Division of Middle Palace Guards.

The Hatakeyama clan in Kii Province and the Kawachi Hatakeyama family (Kingo family [Emonfu, or the Headquarters of the Outer Palace Guards]) … The virtual main line of the Hatakeyama clan which produced many Muromachi bakufu kanrei.
The term comes from kanto of Emon no kami (Captain gate guards.)

Nobushige TAKEDA … Nobushige was a younger brother of Shingen TAKEDA.
The term comes from kanto of Samanosuke (vice-minister of Left Division of Bureau of Horses.)

Nobunaga ODA … The name came from udaijin, the government post of Nobunaga ODA.

Ieyasu TOKUGAWAIeyasu TOKUGAWA, the Naidaijin (minister of the center.)
This term is often used in period dramas.

Hideaki KOBAYAKAWA … Hideaki KOBAYAKAWA, the Saemon no kami and Chunagon (Middle Counselor.)

Masakazu KOBORIMasakazu KOBORI, the Sado (tea ceremony.)
The term comes from Totomi no kuni no kami (Governor of Totomi Province.)

Mitsukuni TOKUGAWAMitsukuni TOKUGAWA, the family head of the Mito Tokugawa family.
The term comes from kanto of Gon Chunagon (Provisional Middle Counselor.)