Plot of Inside Out
A girl named Riley Andersen is born in Minnesota. In her mind, which is commonly referred to as "Headquarters," five personified emotions are created over time: Joy, Sadness, Fear, Disgust and Anger, each one being introduced in this specific order. The emotions are charged with reacting to Riley's circumstances and forming her memories, which are housed in spheres that produce a certain color depending on the emotion of the memory. The most important memories, which are known as "Core Memories," power five "Islands of Personality" that each reflect a different aspect of Riley's personality: Family Island, Friendship Island, Hockey Island, Honesty Island, and Goofball Island.
Each emotion also has a defined purpose in Riley's life: Joy makes sure she is happy, Fear keeps her safe, Anger keeps her life fair and Disgust prevents her from being poisoned, both physically and socially. Sadness, however, doesn't believe she has a purpose in her mind, or that of the other emotions. As a result, she is constantly ignored and kept from using the Headquarters controls, mainly by Joy, who prefers to keep Riley happy as much as possible.
When Riley turns eleven, her family relocates to San Francisco after her father gets a new job. Joy tries to make the move a pleasant experience for Riley and the other emotions, but several events leading up to the move make the other emotions think otherwise. And Sadness messes things up further when she turns a happy memory into a sad one by touching it and causes a core memory to fall out of the container it is housed in. Aware that memories can't be changed back once turned sad, Joy keeps Sadness occupied by having her memorize a stack of "mind manuals" all through the day and into the night.
On Riley's first day at her new school, Joy attempts to keep Sadness from touching anything by having her stand completely still inside a circle of chalk. But Sadness ventures outside the circle and creates a new core memory after making Riley cry in front of her new classmates. Joy attempts to dispose of the new memory, but her struggle with Sadness leads to all the core memories being knocked out from their container. Before Joy can put them back, she, Sadness, and the core memories are sent up a memory tube and into the far reaches of Riley's mind.
As Joy and Sadness make their way through "Long Term Memory," a labyrinth-like place where all of Riley's past memories are stored, they run into Riley's former imaginary friend Bing Bong, who is desperate to reconnect with Riley. When Bing Bong discovers that his song-powered imaginary wagon has been dumped into "the Memory Dump," a pit where obsolete memories are erased, he breaks down in tears of candy and is comforted by Sadness as Joy watches on in confusion. Meanwhile, back at Headquarters, Anger, Disgust, and Fear attempt to take charge in the wake of Joy's absence. But they are unable to make Riley joyful, and instead instigate a confrontation with Riley's parents, and cause Goofball Island to fall into the Memory Dump. The three soon realize that tampering with Riley's personality will cause it to slowly destroy itself with potentially disastrous results.
Joy, Sadness and Bing Bong hatch a plan to ride the "Train of Thought" back to Headquarters and trek through the various parts of Riley's mind, unaware that Riley's life is slowly starting to crumble. She alienates both her parents and her former best friend, struggles in her new surroundings and quits hockey after failing to do well in the first tryout. Anger reasons that the only way to restore Riley's personality and keep the remaining islands from falling into the Memory Dump is to persuade her to run away to Minnesota.
Later that night, while Riley is sleeping, Joy, Sadness, and Bing Bong arrive at the loading dock for the Train of Thought, only to realize the train does not run during nighttime. In an attempt to jump-start the train, the three infiltrate "Dream Productions", where Riley's dreams and nightmares are created. Onstage, they infiltrate a monstrous birthday clown named Jangles, who scares Riley and wakes her up. As Joy, Sadness, and Bing Bong board the Train of Thought and make their way towards Headquarters, Anger enacts his plan of running away. Riley is led to steal her mother's credit card, which causes Honesty Island to crumble, destroying the Train of Thought in the process. Joy, Sadness and Bing Bong take refuge on Family Island only for the island to begin to fall in pieces when Riley boards a waiting bus to Minnesota. Then, after a failed attempt to hitch a ride to Headquarters through an exposed memory recall tube, Joy and Bing Bong fall into the dump, leaving Sadness on her own.
Joy, in despair and on the verge of giving up, bursts into tears and shifts through Riley's memories, locating a sad one in which Riley missed a shot in a hockey game and cost her team the win. Realizing that Sadness was the one who caused both her teammates