Ao Yem, also referred to simply as "Yem", is an ancient Vietnamese bodice used primarily as an undergarment that was once worn by Vietnamese women across all classes.
It is a simple garment with many variations from its basic form, which is a simple, usually diamond or square-cut piece of cloth draped over a woman's chest with strings to tie at the neck and back.
While it was worn across classes, the material and colors used to make Ao yem varied widely based upon the person's rank and the occasion. Commoner women usually wore Ao yem in simple blacks and whites for day to day use, whereas during special occasions they could opt for more festive, brighter colors such as red and pink. Indeed, much of Vietnamese poetry has been dedicated to the beauty of women in their "Yem dao", or pink bodices.