Shitagasane (long inner robe) (下襲)
The term "shitagasane" refers to an inner robe which is put on between ho (outer robe/vestment) and hanpi (sleeveless body wear) when wearers put on a sokutai (traditional ceremonial court dress) or an ikan shozoku (traditional formal court dress).
Summary
While the right side was made of aya (twilled silk) or hiraginu (plain silk) for winter wear, it was made of sha (silk gauze), and the like for summer wear. The reverse side was made of a cloth such as hiraginu which was lustered by itabiki (a luster method for silk).
Its migoro (the main section) is made of two pieces of cloth. Its collar is partially overlapped with itself. Its sides are unstitched. The hem of its back part is made long, and is called tsuzukikyo (long hem).
This hem had been made extremely long since it came to be used to show class differences, and the like. It came to be made separately (separated hem) so that it would not hinder wearers from moving.
While wearers were taking part in an outdoor activity, for example, on an imperial visit, its hem was put behind the sekitai, a leather belt, so that it would not hinder them from moving.
All vassals came to put on a shitagasane with a separated hem in the Kamakura period. But only an emperor and a crown prince put on a shitagasane with an old-style tsuzukikyo.
It was usually put on only when wearers put on a sokutai shozoku (traditional ceremonial court dress). However, in the regents and chancellors period, there was a time when only young male members of the imperial family put on a shitagasane on noshi shozoku (everyday clothes for nobles), which was referred to as 'okimisugata style' (relaxed style with everyday clothes for an emperor or an imperial prince).
Color combinations for shitagasane
Tsutsuji (azalea): While the right side is white, the reverse side was originally dark suo (deep dark red), but later it has been changed to black. It was usually used by persons in young and middle ages.
Yanagi (willow tree): While the right side is white, the reverse side is ao (present-day green). It was usually used by persons in old age.
Kobai (rose plum): While the right side is kobai (dark pink), the reverse side is suo (dark reddish purple). It could be put on from the winter to the middle of the spring, and was used for events of the New Year, and so on.
Matsugasane (pine tree layers): While the right side is ao (present-day green), the reverse side is purple. It was used to attend an emperor and members of the imperial family or to hold a Kurabeuma (horse racing).
Kimomiji (yellow autumn leaves): While the right side is yellow, the reverse side is suo. It could be put on from September to November, and was used on formal occasions such as a ceremony, a feast, or the like.
Kiku (chrysanthemum): While the right side is white, the reverse side is suo. It could be put on from October to November, and was used on formal occasions.
Urayamabuki (a Japanese rose seen from the underside): While the right side is yellow, the reverse side is deep red. It could be put on from the winter to the spring, and was used on imperial festivities, imperial visits, and so on.
Sakura (cherry tree): While the right side is white, the reverse side is ebizome (burgundy or wine red). It could be put on in the spring, and was used on formal occasions.
Ebi (grape): While the right side is suo, the reverse side is hanada (light blue). It could be put on from the winter to the spring, and was used on ceremonies such as an imperial visit to Kasuga Shrine.