Yusoku Kojitsu (Ancient Court and Military Practices) (有職故実)
Yusoku kojitsu is the study of government positions, ceremonies, and costumes based on their ancient precedents. Yusoku' means a knowledge about past precedents, while 'kojitsu' means a convincing basis and norms for the rights and wrongs of public and private acts. People who are well versed in such knowledge were called yusokusha. This later became "yusoku."
Today, people with deep knowledge and insight are called "yushiki-sha," which is a legacy of this.
Kuge Kojitsu (Court Practices)
The systematization of knowledge on precedents had advanced since the mid-Heian Era, and two schools, the Ononomiya School and Kujo School were established. The Koichijo School subsequently arose followed by the establishment of the Mido School branch of the Kujo school later. It is thought that there was also the Tsuchimikado School (Murakami-Genji (Minamoto clan) line) founded by MINAMOTO no Moroyori and the Hanazono School (the Kanin School line) founded by MINAMOTO no Arihito and perfected by his relatives Sanesada TOKUDAIJI and Sanefusa SANJO during insei period (during the period of the government by the retired Emperor). The Tokudaiji family (Kujo school) and the Oinomikado family (Mido School) who governed Yusoku kojitsu subsequently emerged.
While yusoku kojitsu originated from government-regulated books on rites, nobility recorded yusoku kojitsu in their diaries and their descendants collected ancestral diaries to compile yusoku kojitsu. Among books on yusoku kojitsu, the three books "Saikyuki" written by MINAMOTO no Takaakira, "Hokuzansho" written by FUJIWARA no Kinto, and "Goke-shidai" written by OE no Masafusa were respected as 'kosei no kikan' (a paragon for the future generation) and treated as special cases. Kaneyoshi ICHIJO of the Muromachi period recorded that "Saikyuki" is about old ceremonial styles, "Hokuzansho" is about ceremonies during and after the era of Emperor Ichijo, and "Goke-shidai" is about ceremonies during and after the era of Emperor Gosanjo.
After the Kamakura period, yusoku kojitsu became as specialist field and the subject of active research, leading to the authorship of books including those on ceremonies such as "Kinpisho" written by Emperor Juntoku, "Kemmu Nenchu Gyoji" written by Emperor Godaigo, and "Kuji kongen" (the Rules of Court) written by Kaneyoshi ICHIJO; those on the government system such as "Shokugensho" written by Chikafusa KITABATAKE; and those on clothing such as "Masasuke Shozoku Sho" (Masasuke's rule book on costumes) written by MINAMOTO no Masasuke. Well-known researchers of famous kuge (court nobles) include Kinkata TOIN and Yoshimoto NIJO in the period of the Northern and Southern Courts (Japan), Chikanaga KANROJI in the Muromachi period, and Mototada HIRATA in the Azuchi-Momoyama period through to the early Edo period.
Buke Kojitsu (Military Practices)
Kojitsu of warriors (Bukankojitsu) was passed down by the Ki and Tomo clans during the Heian period, but went into decline as the samurai class rose.
In Kamakura period, MINAMOTO no Yoritomo highly regarded warriors who were very aware of kojitsu and tried to restore kojitsu.
Subsequently, bukankojitsu introduced from Kyoto in piecemeal fashion and the traditional customs of warriors in the Kanto region were blended and systemized to create buke-kojitsu (military practices.)
Within buke-kojitsu, there was practical kojitsu on kyuba (archery and horsemanship) and battle as well as kojitsu on ceremonies and manners for when in front of the bakufu (Japanese feudal government headed by a shogun) or one's lord, and while the former became perfunctory due to changes in military tactics, the latter blended with kuge kojitsu and spawned the Ogasawara school and Ise school.
During and after the Edo period, researchers of yusoku kojitsu emerged among ordinary citizens along with the development of the study of classical literature, and made original studies free from the traditions of kuge and buke yusoku kojitsu, which showed stagnation as academics because they were transferred by heredity. Although Yoshichika TSUBOI of Kawachi Province was an ordinary citizen, he was considered top of the field of research into official posts and costume, and it is said even kuge sat at his feet. Within the field of kuge kojitsu research, academic standards were raised by Sadamoto NONOMIYA, Kinkazu SHIGENOI, Mitsuyo URAMATSU (Kozen URAMATSU) and others as if they were inspired by Tsuboi. Well known researchers of buke kojitsu include Munetake TAYASU, Sadanobu MATSUDAIRA and Hokiichi HANAWA.
Within the field of buke-kojitsu, in addition to Sadatake ISE (the Ise clan), who is said to be a leading figure of Edo period buke kojitsu and who wrote many books, other renowned researchers include Hakuseki ARAI who wrote "Honcho Gunkiko" (a review and classification on historical weapons), Nagatoshi SAKAKIBARA (a disciple of Sadatake ISE), and Nobuna NAKAYAMA (a disciple of Hokiichi HANAWA).
In modern times, the history of yusoku kojitsu study in a practical sense ended as the conventional kuge and buke system was abolished. In addition, the study of governmental regulations became part of legal history. Even so, studies continued as part of history and Japanese literature research, and outstanding researchers such as Jojitsu SATO and Hidematsu WADA emerged.