Childhood sweethearts meet in school as Korean children in Past Lives. Greta Lee plays Nora, whose family elects to immigrate to America. Teo Yoo plays Hae Sung whose family stays. Twelve years later the two reconnect on social media as young adults. She has become a modern American woman. He remains culturally Korean. They talk and she decides to stop. Twelve more years pass, and he comes to New York to visit. Even though she has married and is pursuing a career as playwright and teacher, she's curious. Past Lives explores a number of "What Ifs." What if she stayed? What if he immigrated? Would they be together? Why do they still care for each other? Past Lives will linger long after you watch. You might call a former lover. Or not.