Nakanooe defeated the Soga family changed the government system from
family-oriented to the Imperial-family-oriented. In this period, Tang
China had a territorial ambition to invade Kokuryo Korea. In the
meantime, Kudara Korea was on the decline and Silla Korea was on the way
to unify the Koran Peninsula. In order to deal with the gravity of the
situation change, the new dress regulation was adopted.
The dress regulations of the Suiko Dynasty let the head of family take
the practical position in the national politicfal scene just like the
officers ranked under state councilor with senior grade of the fourth
court rank in later ages. After the fall of Soga family, the new
regulation was adopted in the third year of Taika Dynasty [647 A.D.],
established the senior and junior rank of shokukan, shukan and shikan.