Successful Ryoo Seung-yong comes back as a fool Yong-gu for his daughter! Outsiders not allowed! In room number 7 of the prison where all kinds of criminals are gathered, comes Yong-gu, a father with the sense of a 6 year-old and his 7 year-old daughter Ye-seung. The mission of these criminals in room number 7 is to protect these two who can never stay apart for a single moment. Will they succeed?