Wikipedia
Gomusin are a traditional type of Korean women's shoe. The term "Gomusin" is also used as a social designation; in this sense it refers to young Korean women who are waiting for their boyfriends to return from the compulsory, two-year service in the South Korean army. Its origin comes from gomsin, which means "wear the rubbers back to front". The word is an abbreviation of Gomusin. Since all Korean men are obliged to serve in the army, it is common to find gomsin among Korean women who are between twenty and thirty years old.
"Wearing gomsin" or "putting on gomsin" is slang widely used online in Korea. There are terms to describe men, such as "combat boots". When a girlfriend remains devoted to her boyfriend throughout his service, they may be called "wearing kkotsin." Kkotsin are a type of flower shoe.