The Kramers are like an ordinary American couple. Mr. Kramer (Dustin Hoffman) works outside to earn money, while Mrs. Kramer (Meryl Streep) takes care of their 6-year-old son Billy (Justin Henry) at home. Because Mr. Kramer was busy with work and neglected his family, Mrs. Kramer ran away one day, leaving the father and son behind. Mr. Kramer is now busy with work and taking care of Billy, and his life is in trouble. Mr. Kramer is not good at housework and makes a fool of himself when taking care of Billy: the first time he fried French toast for Billy, the process was very scary; Billy didn't want to eat but wanted ice cream, Mr. Kramer wanted to stop him but didn't know how to communicate... Fortunately, with the help of his female neighbor, Mr. Kramer gradually adapted to the life of a single father. The father and son became closer and more dependent on each other. At this time, Mrs. Kramer came back. She was already an outstanding designer in New York. She came back to take back the custody of Billy...