As Mofuku has been a formal mourning dress, people wore Nagagi on top of a white undergarment in olden times, but these days, partly because the formal dresses are being simplified, and partly because people observe a taboo against wearing layers of clothing that may be associated with having another mourning, an undergarment is not used for Mofuku.
古来は喪の礼装であるため、長着の下に留袖と同じく白い下着（重ね）を着ていたが、現在では礼装の軽装化と「喪が重なる」と忌むことなどもあり下着は用いられないのが一般的である。