@lama, @heirress, it's a probiotic diary product. it's fermented skimmed milk with a strain of bacterium Lactobacilus. it's supposed to restore the flora in your intestines, regulate bowel movements, help with constipation. a well known brand it's Yakult, Japanese product. The Lactobacilus casei strain Shirota was discovered by Dr. Minoru Shirota.
at first, you might not like the taste, but after a while it's not bad.
@dramacrazy Soju, Yakult, a couple ice cubes, and a quick splash of Sprite or 사이다 (Chilsing Cider aka Korean Sprite). But if I had a flavored Yakult (which can be found in a lot of Asian supermarkets), I probably wouldn't use Sprite. It's pretty sweet on its own!