Ifemelu lives a frustrated life in Nigeria, her college classes constantly cancelled due to strikes. Seeing no end to the tumult, she joins her cousin in America--and discovers race. Suddenly she is black, and that fact has a total effect on her new life. It changes her relationships, her job prospects, the way she relates to her family back in Nigeria.
Ifemelu's college boyfriend, Obinze, finds himself struggling to make a life in the UK where, despite his intellectual inclinations, he is forced to work for shipping company after shipping company, never able to stay in one place for long and hoping that his employers never discover his undocumented status.
Fifteen years later, Ifemelu prepares to move back to Nigeria, where Obinze has long since returned to live a wealthy, superficial life among corruption and loveless relationships.
Over the course of years, Adichie follows the breaking of her protagonists' connection, and the process of trying to reforge it, all amongst the twisted, centuries-old, beautiful, horrifying mess of race in America from the unique perspective of an outsider upon whom this complex burden has been forced without context.