Ifemelu comes to America as a young woman and finds success as a blogger on race. As a black woman from Africa rather than an African American, she is simultaneously categorized with black Americans while having a different history and having grown up in a different context. Obinze, the man she left behind in Nigeria and with whom she cut off contact sometime thereafter, lives as an undocumented worker in London. Their stories largely told in flashbacks, both eventually return to Nigeria changed.
This book simultaneously addresses cultural clashes directly and maintains the individual stories of all the characters (Ifemelu's family in particular, in addition to the two main protagonists) as people. It was deeply engrossing, and at this point I think the best thing I can say is a simple "read it."