Believing that she is Riley's most important emotion, Joy always tries to take the lead. Prevented from playing her role in Riley's emotional development, Sadness feels annoyed. When Riley moves to a new city, she has a hard time adjusting to her new surroundings. Sadness wants to do her duty but by accident causes the loss of Riley's happy core memories with Joy.Now separated from her friends and her beloved hockey team,Riley starts to feel lost and helpless, and wants to run away from her parents and new school. Worried about her, Joy and Sidness try to work together to ensure she gets her core memories back.Eventually,realising that every emotion has a role, Joy understands it is okay for Riley to feel sad sometimes.Accepting sadness as part of life helps Riley deal with the emotional complexity of growing up, and sttle down in her new life.