It tells the story of a group of different people, some of whom have the same birthday, and their life stories intersect in an interesting way. Mandy Moore plays Rebecca, Jack's lovely wife and best friend. After moving to Pittsburgh, she gave birth to triplets. Milo Ventimiglia plays Jack. Justin Hartley plays Kevin, a handsome and popular TV actor who has an extremely boring and endless single life. Sterling Brown plays Randall, a well-dressed family businessman working in New York. He and his wife Beth work closely together to raise two daughters. Susan Kelechi Watson plays Beth, Randall's wife Ron Cephas Jones plays William, Randall's biological father. He abandoned Randall when he was born. Chrissy Metz plays Kate, who, like many women, is troubled by diet and body shape. She uses sticky notes all over the apartment to control her diet. She is Kevin's twin sister, but she is completely opposite to Kevin in every way.