This frothy romantic comedy from Korea begins with Kyun-woo, a ne'er-do-well college student, meeting a very drunk girl on a subway platform. After he helps her onto the train, she promptly vomits on another passenger's head (twice) and then passes out. Since everyone else in the train car assumes that she's his girlfriend, he carries her to a hotel room to sleep it off. Another series of mishaps brings a police raid while he's in the shower, and thus begins a wild roller coaster rise of a relationship. The rest of the move has her putting him through a battery of often humiliating tests to prove his love.