This is the most formal of hakama, worn as part of the sokutai (under both the ketteki no hô and hoeki no hô). The name means “over pants” and can also be read “Ue no hakama.“
It is always white (its other name being “shirobakama,” or “white hakama”), and always lined in unpatterned kurenai silk. The lining always shows around the edges of the ties, and at the hems.
Unlike conventional hakama, the ties are not pared front and back; rather, there is but one long waist tie, and the front is permanently attached to the back at the right and left sides, as the actual opening is up the front, which is covered by the joining “fly.” The waist tie overlaps at the front, and is tied closed at the right side, with the excess of the waist ties thrust into the pant leg. This is the opposite of the ôguchi, which is worn under this garment.
The uwabakama is totally open along the crotch; in fact, it is almost two separate garments — a left leg and a right leg — joined at the center back. There is a long, solid panel that runs up between the legs. Each leg is two widths of cloth, making this a four-panel hakama.
The standard pattern for the imperial family, kugyô, and others with permission to wear “forbidden colors” is ka ni arare. The actual motif inside the “ka” (the island, so to speak) varied. Sometimes it was a karahana, mukaichô, kiku, etc. Those below the rank of denjôbito wear unpatterned white uwabakama when the occasion arrises to wear them.