Bart's coming of age story, a la "Boyhood," chronicles his life from six years old to his time as an accomplished young man. Along the way, his tense relationship with Homer, an overly uncaring version of himself, and Lisa, who overshadows him in every way possible, shape Bart more than he realizes.

A new teacher at Springfield Elementary, and a captivated Bart tries everything to win her over. Meanwhile, Homer decides to buy a new brand of "milk," which causes early puberty, both for Bart (augmenting his wooing powers) and Lisa (whose small bout with acne opens her up to the world of makeup and popularity).