The Vietnamese ao dai is the country’s national costume. Although ao dai literally translates as ‘long shirt’, it is actually a long-sleeve, long-flap, tunic top worn over blousy high-waisted pants. It is to Vietnam what the kimono is to Japan and the hanbok to Korea. 1. “It covers everything but hides nothing.” That says it all. Indeed, the ao dai is one of the sexiest dresses in the world, especially when cut thin and soft from silk or satin so that it looks like it’s flowing. The top is tight-fitting, which showcases the curve of the wearer.