Hyun-woo is a webtoon writer who is popular and handsome, but does not believe in love. He has an assistant Seul-bi who is cute and chubby. Seul-bi has a crush on Hyun-woo for a long time, but she has never told Hyun-woo about her feelings. One day, Seul-bi drinks a cup of magic coffee and turned into a beautiful woman. She names her transformed self Oh Go-woon.