The iromuji is a crested single-colored kimono. With five light, undyed crests, it is considered a formal kimono. With three crests, it will be considered more formal than a tsukesage or a houmongi without crests, but there are not many occasions where it will be appropriate for. With one crest, it will be considered a semi-formal kimono, and can be worn to various events such as a friend’s or colleague’s wedding ceremony or a child’s school enrolment or graduation ceremony. A crested muji is usually worn to tea ceremony or ikebana lessons. It can also be worn with a hakama to a graduation ceremony. Embroidered crests can be applied without changing the formality.
An iromuji can be changed by dyeing it to a different color or adding designs to the lining. Also, it is possible to create an outfit to show off an obi by wearing the obi with an iromuji. Both a formal outfit or a fashionable coordinate can be created by matching the kimono with a fukuro obi or a Nagoya obi respectively.
Iromuji made with jimon (woven pattern), muji chirimen (crepe) or yusoku jimon are worn to a tea ceremony or as a formal kimono, but there are also iromuji with jimon made for mourning. Iromuji with kissho mon (good luck prints) or auspicious patterns should not be worn for mourning even if they are made of a plain or dark color.