I'm assuming you are referring to the fictional novel, Matched by Ally Condie? It's a dystopian novel about a sixteen year old girl, Cassia, who lives in a world where every
…one is matched by Society with a person who will become their lover. Their society is simplified by having only a hundred things of each aspect in history (eg. 100 poems, 100 pictures, 100 songs...) because they believe that the society before theirs (referring to time now) was too overcrowded with information. Cassia is matched with her best friend Xander (a rare situation) but she becomes confused when society has made a mistake by giving her the information card (that everyone gets of their match) of another boy- Ky who is also her friend and an aberration (a person who cannot be Matched). She then falls in love with Ky instead of Xander and they form a strong bond through various events. Society has actually done this on purpose to see what happens and through the story, Cassia realises how bad society actually is (also hears of a rebellion). Ky is then taken to the outer provinces and the story continues as a trilogy (Crossed and Reached). (MORE) 
