In ancient Japan, it was customary to place flowers, branches, and leaves of plants and trees as hair ornaments on the head, sometimes wrapped around it.
"[1][a] Also, according to the article of December 603 in Nihon Shoki (Chronicles of Japan), on the first day of the year, uzu (髻花) was attached to the crown.
[3] The floral arabesque design of the outer crown is thought to be descended from the ancient uzu and kazura, as well as from the Twelve Level Cap and Rank System.
[4] According to the clothing regulations for military officials in the Yōrō Code, the ceremonial crown for military officials is described as a black silk gauze crown (皂羅冠, kuri no usuhata no kanmuri) with black horsehair fan ornaments (皂緌, kuri no oikake).
In later periods, military officials wore black gauze crowns adorned with fan-shaped decorations called oikake on both sides.
According to Fujiwara no Sadanaga’s Record of the Enthronement of Emperor Go-Toba, the bureikan is described as follows: “A black cap is worn beneath the crown.
According to the Record of the Enthronement Procedures (御即位次第抄), found in the Imperial Section of the Kojiruien (古事類苑), the bureikan was made from purple silk and fashioned into a five-peaked crown.