Riley is now a teenager, navigating the tumultuous world of high school with its social pressures and academic challenges. Her core emotions – Joy, Sadness, Anger, Fear, and Disgust – continue to guide her through life's experiences, but begin to face new and more complex emotional developments. As Riley encounters first loves, newfound independence, and the anxieties of growing up, her mindscape becomes a more intricate and sometimes chaotic place. Joy tries to maintain the balance in Riley's emotional headquarters, but the emergence of new feelings like Embarrassment and Guilt creates unexpected turmoil. The headquarters team struggles to integrate these new emotions while trying to keep Riley confident and content.

As pressures mount both at school and home, Riley's relationships with friends and family become strained. The emotions must learn to work together in new ways to help Riley manage her increasingly complicated life. When an external event threatens to throw Riley into emotional overload, the core emotions realize they need to adapt their strategies to support her more effectively. They embark on a journey through Riley's evolving mindscape, discovering new islands of personality and revisiting old memories, learning valuable lessons about growth and resilience. Through teamwork and understanding, they aim to help Riley find balance and happiness amidst the chaos of adolescence.