Sokutai

The sokutai (束帯) is a traditional Japanese outfit worn only by courtiers, aristocrats and the emperor at the Japanese imperial court. The sokutai originated in the Heian period, and consists of a number of parts, including the ho (outer robe), shaku (笏), a flat ritual baton or sceptre, and the kanmuri (冠), a cap-shaped black lacquered silk hat with a pennon.
The exact composition of the sokutai differs from person to person, and depends on a person's rank and whether they are a civil or military official, with military officers wearing the garment's outermost layers with split front and back panels, and civil officials having fully sewn panels. Colour also varies by rank, with colour symbolism having held great importance in Heian period Japan.
No longer worn as everyday clothing, the sokutai is preserved as formalwear worn by male members of the Imperial court, including the Imperial family and government officials, such as the Prime Minister. The sokutai is typically reserved for the most formal occasions, such as weddings and enthronement ceremonies. On such occasions, women such as an empress or princess wear a jūnihitoe, the sokutai's female counterpart.
The Japanese emperor's court dress is made up of loose-fitting white trousers and a loose yellow outer robe that is styled after a Chinese robe but is tucked in at the waist, and decorated with the textile pattern consist of Fenghuang, Paulownia, Bamboo and Kirin. When wearing the sokutai, the emperor carries an ivory tablet, inspired by the Chinese Hu, which was carried by Chinese emperors as a symbol of imperial power.
Similarly to the jūnihitoe, the sokutai uses colour symbolism, though unlike the jūnihitoe, colours are more restricted, specifically denoting court rank:
Persons without rank typically wear mud brown or light yellow; the darker, fuller shade of yellow was reserved for the emperor. Though exact shades varied highly, with a number of colours detailed as having minuscule shade differences and thus different names, the highest-ranking shades were all achieved through dyeing fabric with the gromwell plant, an expensive and prolonged process that could take over a year to achieve. Due to the difficulty of obtaining a number of dyestuffs used to produce the purple and maroon colours worn by the highest-ranked officials, these colours were changed to black sometime during the Heian period.
The innermost layer of the sokutai was the kosode (小袖, lit. 'short sleeve'), a white garment that covered the wearer to knee level. This was worn with a pair of ōkuchi-hakama, a pair of long red hakama worn on top of the kosode and tied off to the wearer's left. Similarly to the jūnihitoe, which used a white kosode and a pair of red hakama as a base layer, both of these would have been worn as both undergarments and sleeping clothes.
A hitoe (lit. 'unlined garment') was worn over the top of the kosode as an upper garment; a number of layers of akome were worn above the hitoe, the exact number and fabric of which varied based on the season. The ue-no-bakama, a shorter white hakama with an open fly, was worn above the akome, tied off to the right. The shitagasane, a typically white garment with the characteristic "tail" of the sokutai, was worn on top of the akome, covering the upper body of the wearer. The hampi—a sleeveless vest often featuring embroidery—was worn over all these layers. The final outer robe—the ho—was then worn over the hampi; this outer robe followed the design of the Chinese yuanlingpao in its cut, but with a distinctively Japanese style, with the robe tucked at the waist, such that the hemline ends midway between the knees and floor.