The Omiya Family (大宮家)
They were jigeke (lower rank court officials) who used the family name of Otsuki (also Ozuki). They were known as a kanmu family (a family whose members were allowed to hold top government posts).
The Omiya family was a Japanese clan who were kuge. It was a branch family of the Saionji family, which belonged to the FUJIWARA no Kimisue line (the Kanin line) of the Northern House of the Fujiwara family. They held the rank of Urinke (which entitled them to hold military ranks). The family's kamon (crest) was hidari mitsudomoe (a counter-clockwise pattern comprising three comma-shaped figures in a circle) (the same as that of the Saionji family).
Suehira OMIYA (who served as Udaijin, or Minister of the Right) was the second son of Kinhira SAIONJI, who served as Sadaijin (Minister of the Left) during the mid-Kamakura period. Suehira branched out from the Saionji family, adopting Omiya as his family name. Suehira's family line was interrupted. During the early Edo period, however, the Omiya family was revived by Suemitsu OMIYA (who was a member of the konoefu, or Inner Palace Guards), the second son of Kinmasu SAIONJI (who served as Naidaijin, or Minister of the Palace). His karoku (hereditary stipend) was 130 koku. Suemitsu was confined to his house when he became mentally ill, however, and passed away in 1684. Konoefu Masasue OMIYA (1743 - 1804) was the first of this family line to become a kugyo (high-ranking court noble) when he was awarded the rank of Shosanmi (Senior Third Rank). During the Edo period, Morisue OMIYA (1768 - 1835) held the position of Chunagon (Middle Counselor) and was awarded the rank of Shonii (Senior Second Rank), which was the highest rank ever achieved by any member of the family. During the Meiji period, the family was raised to the peerage, and Mochisue OMIYA became a viscount in 1884.
The Omiya family (the Otsuki clan)
The Omiya family is a family line whose members became government officials and served at the Imperial Court. It entered into a dispute with the Mibu family about which family should become the main branch of the Otsuki clan. The patriarch was Hirofusa OTSUKI. The family acquired the name 'Omiya' because they possessed a mansion in Tsuchimikado Omiya for a long time.
The Otsuki clan had been responsible for record keeping for the Daijokan (Grand Council of State) since medieval times. Because the government position of Sadaishi Joshu (Chief First Secretary of the Left, or Senior Recorder of the Left), which held the rank of Goi (Fifth Rank), was hereditary, the family was known as a kanmu family. However, during the late Heian period, OTSUKI no Takamoto fell from favor with MINAMOTO no Yoritomo. As a result, OTSUKI no Takamoto was replaced as Sadaishi Joshu by Hirofusa, the son of Takamoto's older brother, OTSUKI no Naganari. Later, after Takamoto was returned to his job, the government post of Sadaishi Joshu was held by whichever descendant of Hirofusa (i.e. the Omiya family) or Takamoto (i.e. the Mibu family) became head of the Otsuki clan. The dispute between the two families continued, however. In particular, the feud between Nagaoki OMIYA and his son Tokimoto OMIYA on the one side, and Asateru MIBU and his son Harutomi MIBU on the other was intense enough to necessitate the involvement of the Imperial Court and the Muromachi bakufu (Japanese feudal government headed by a shogun).
Nagaoki OMIYA's promotion to the position of jibukyo (Minister of Civil Administration) meant that he was the first person from the clan to be appointed a minister of one of the eight central ministries, and he made a great effort to revive the family name. As a result of the Onin War, however, he lost the Omiya family library, which contained a number of ancient documents and was effectively the source of his authority as a government official. In contrast, Harutomi MIBU managed to protect his documents and later rebuilt the Mibu family library. Because the Omiya family lost the ancient documents in their kanbunko, which was an accumulation of works from the past generations, it became difficult for the Omiya family members to work as government officials after Nagaoki's death. Tokimoto's son, Koreharu OMIYA, left the capital to go to Suo Province in order to seek help from the Ouchi clan. Koreharu's daughter was favored by Yoshitaka OUCHI, and she bore him an heir who was also called Yoshitaka (the Japanese kanji used to write his name was different, however). In 1551, however, the Omiya family was attacked and destroyed by Takafusa SUE, who raised an army in rebellion against Yoshitaka OUCHI (an event known as the Taineiji Incident).