The movie follows Riley, an 11-year-old girl, who is guided by her five emotions: Joy, Sadness, Fear, Anger, and Disgust. Riley's life changes when her family moves from Minnesota to San Francisco. Initially, Joy tries to keep Riley happy, but the move makes her feel lonely and disconnected as she struggles with her new home, school, and friends.
Things spiral out of control when Joy and Sadness accidentally get lost inside Riley’s mind, leaving Anger, Fear, and Disgust to manage her emotions. As a result, Riley becomes emotionally distant and considers running away back to Minnesota.
Joy realizes that Sadness plays a crucial role in helping Riley process her feelings and connect with others. By embracing her sadness, Riley opens up to her parents, who comfort her, and she begins to adjust to her new life. The movie teaches that all emotions, even the difficult ones, are important in creating meaningful connections and a sense of belonging.