When twenty-seven year old Roxy Rule's best friend and roommate accepts a glamorous new job overseas, she expects their relationship to continue as it's always been - carefree and easy - until they share a heart-stopping kiss. While Ollie escapes to jolly ole England to live out his dream and save the planet with green architecture, Roxy is stuck in New York City working for a boss who makes her want to stab herself with a letter opener. She can't bear to think about her own big-city dream of being a chef anymore. Over the years, her passion for food has only resulted in extra pounds and a staggering credit card balance for fancy kitchen equipment that she barely has time to use. Still, Roxy's sure that nothing can come between two lifelong best friends - not even mild jealousy over a thriving career or a silly little kiss that meant nothing.

In fact, it was such a meaningless and forgettable kiss that it's not worth mentioning to her fiance not that he would even listen - all they do these days is argue about their upcoming wedding. Roxy is faced with an unexpected family reunion when her younger sister Steffi arrives on her doorstep, six months into a pregnancy she refuses to discuss. When older sister Izzie - in the throes of a premature midlife crisis - joins them, she's determined to crack the case of Steffi's impending motherhood.

With the Rule sisters living under the same roof again, Roxy's quiet little apartment in the city is about to be anything but peaceful. Roxy soon discovers that her seemingly idyllic relationship with Ollie started getting complicated way before he left for London. She must come to terms with her feelings for him, learn to stand up for herself and go after what she really wants. Breaking the Rules is the story of what happens when you have to redefine the rules of love, friendship and family in order to find yourself.