In early 20th-century London, Henry Higgins, an arrogant, world-renowned phonetics professor, makes a bet with his friend Colonel Pickering that he can transform Eliza Doolittle, a spirited but uncouth Cockney flower seller, into a refined lady who can pass as a duchess at an ambassador's garden party. Intrigued by the challenge and enticed by the prospect of a better life, Eliza agrees to undertake Higgins' rigorous training. The process is grueling, as Higgins employs a variety of teaching techniques to scrub away Eliza's thick accent and replace it with aristocratic enunciation. Despite their clashes, Eliza starts to show progress.

As Eliza's transformation unfolds, she endures the struggles of adopting upper-class mannerisms and speech. Meanwhile, her relationship with Higgins grows more complex, vacillating between antagonistic and collaborative. She experiences growing pains in her new social role, and her personal identity begins to shift. Simultaneously, Higgins must confront his own prejudices and preconceived notions about class and gender as he watches the profound change in Eliza. The initial stages of her metamorphosis culminate with her debut in society, where her true test as a lady of high standing awaits.