While You Were Sleeping

Yu-jin is a single girl with lots of boyfriends. One morning she wakes up and finds herself in a hotel room with a faint memory of having slept with a man in the previous night. She had a wild party and got drunk to the point where she couldn't tell whom she was with, so she makes a list of several potential suspects. Cheol-jin was among them, who has been one of her best friends since college, but she's convinced that it couldn't be him because he's too shy for anything like that.