The film is divided into two chapters, each exploring a pivotal period in Adèle's life. The first chapter introduces Adèle (played by Adèle Exarchopoulos), a 15-year-old high school student struggling to find her place in the world. She meets Emma (played by Léa Seydoux), an older and more confident art student, and the two begin a romantic relationship. As their relationship deepens, Adèle becomes increasingly dependent on Emma, leading to a tumultuous and passionate, yet ultimately doomed, romance.