Naomi and Ely have been inseparable since childhood—partially because they've grown up across the hall from each other in the same Manhattan apartment building, and also because they're best friends. Soul mates. Or are they? Just to be safe, they've created a No Kiss List—their list of people who are absolutely off-kissing-limits for both of them. The No Kiss List protects their friendship and ensures that nothing will rock the foundation of Naomi and Ely: the institution.

Until Ely kisses Naomi's boyfriend. And a fateful piece of gum in the wrong place at the wrong time changes everything.

Soon a rift of universal proportions threatens to destroy their friendship, and it remains to be seen whether Naomi and Ely can find their way toward new soul-mate prospects... and back to one another.

Rachel Cohn and David Levithan have written a love stroy about love of all kinds, one that reminds us that any great friendship can be as confusing, treacherous, inspiring, and wonderful as any great romance.