Romy and Michele have been best friends since high school and have always felt like outsiders. They live together in a small apartment in Los Angeles, where they spend their days watching TV and dreaming about their future. When they receive an invitation to their high school reunion, they decide to attend and show everyone how successful they have become.
However, Romy and Michele are not actually successful and have not achieved anything in their lives. To impress their former classmates, they create a fake story about being the inventors of Post-It notes, hoping to gain the admiration and respect they have always craved.
At the reunion, Romy and Michele realize that their classmates have not changed much since high school. They are still shallow and judgmental, and the girls struggle to fit in. They meet former classmates who remind them of the bullying and exclusion they experienced in high school, including the popular girl who stole Romy's boyfriend and made Michele sell her soul to get her attention.
As the evening progresses, Romy and Michele's lies catch up with them, and they are exposed as frauds. They are rejected by their classmates once again, and the girls start to question their friendship and their lives. After a heart-to-heart conversation, they come to the realization that they don't need anyone else's approval or validation to be happy. They leave the reunion on their own terms, with their heads held high and their friendship stronger than ever.