The “deep robe,” or simeui (심의, 深衣) was worn by Confucian scholars while studying and performing rites. It was introduced along with Neo-Confucianism from China during Korea’s Goryeo dynasty. The sober aesthetics of the robe were consonant with Confucian values and was promoted by the Chinese sage Zhu Xi as standard menswear. It consisted of the upper eui (衣) attached to a skirt (sang, 裳), which was made up of 12 panels of fabric sewn together.
The robe ultimately descended from the zhiju shenyi (直裾 深衣) worn in ancient China. By the Ming dynasty, it was considered ultra formal wear. In Korea, the use of the simeui for ancestral rituals was eventually replaced, for the most part, by the dopo (도포, 道袍), another Sino-Korean robe.