After OTSUKI no Tomochika was appointed Sadaishi corresponding to Fifth Rank, the Otsuki clan (the Mibu family, the Omiya family) served as Daishi Joseki, which was Kanmu, for generations, being in charge of keeping the transmission of records and documents of Daijokan under the name of 'Kanmu family.'
小槻奉親が五位の左大史に就任して以後、小槻氏（壬生家壬生家（小槻姓）・大宮家大宮家（小槻氏））は代々にわたって大史上席（官務）を務めたため、「官務家」と称され、太政官の記録・文書の伝領保存の任にあたるようになる。