So both share a theme of Girl who pretends to be a boy for such and such reason falls in love with some guy.
You are beautiful is about a girl whose twin brother successfully wins the "A.N Entertainment" vocal auditions for musical band "A.N.JELL," but he must leave in order to correct his botched plastic surgery in the United States. His manager,her to pose as her brother for a month till he recovers. She is against it at first, but eventually agrees, as a path to fame would give the twins an opportunity to find their mother.
Coffee Prince is about a girl who is always mistaken for a boy. She gets a job at a coffee shop that a guy she knows is running (he thinks she is a boy) and because the shops theme is princes they only hire men. So she hides her true gender in order to keep the job she need to provide for her family. Meanwhile she falls for the coffee shop manager and thats pretty much where all the fun comes in.