Asagai really works the Nigerian thing to get ahead with Beneatha. Knowing that Beneatha has a longing for identity and roots, he tells her all about Africa and gives her African records and a robe. If Asagai had his way, she'd be a straight-up African woman, instead of an African-American one. He even goes so far as to suggest her straightened hair is a sign that she is "assimilated" into white American culture.
Eventually, Asagai proposes to Beneatha and asks her to come back to Nigeria with him. In the play's final scene, Beneatha is seriously considering his proposal. We never find out if these two lovebirds run off into the African sunset together, but we hope it works out for them.
Asagai's main function as a character seems to be to inject the play with symbolism. Basically, Asagi is Africa. He represents one extreme of the American debate on assimilation. His presence in the play forces the audience (and Beneatha) to ask what it truly means to be an African American. How can blacks live in America yet retain some of their unique cultural identity? Is it possible?