Welcome to Pia Carrot (Pia♥キャロットへようこそ!! pia♥kyarotto he youkoso) is a Japanese visual novel series by Cocktail Soft (a part of F&C, later F&C FC02). The games are all set around restaurants in the fictional "Pia Carrot" chain, and most of the female characters are waitresses at these restaurants. The individual restaurants in the chain are called "1st", "2nd", etc. The series is an eroge and anime have been based on it.
(source: Wikipedia)