After spending several years in the shadows, admiring women from afar, a middle-aged man named Grant comes to realization that his infatuation is not a desire FOR women, but to actually BECOME a woman.
He seeks an interracial casual encounter with a craigslist stranger who is a well-to-do doctor. You could say the alpha black doctor ends up playing a "big" part in his journey, and is essentially provides a "slice" of life.
Feminization is making one effeminate (usually just crossdressing), whereas Transformation implies a more permanent change.