Riley’s family moved to San Francisco due to her father’s job, and she had to prepare to adapt to the new environment. But at this moment, the two brain ministers Lele and Sadness, who controlled happiness and sadness in Riley’s mind, were lost in her mind. , only three officers in charge of anger, fear and disgust are left in charge of the brain headquarters, causing the originally optimistic Riley to become a cynical girl. Lele and Youyou must return to the brain headquarters as soon as possible in the complex world of the mind, so that Riley can regain her original happy and normal emotions
