Two years after her move to San Francisco,Riley, now 13, is about to enter high school. Her personified emotions — Joy, Sadness, Fear, Anger and Disgust — have since overseen a newly-formed element of Riley's mind called her "Sense of Self", which houses memories and feelings that form Riley's beliefs. Joy, intending to fill the Sense of Self with only positive memories, has invented a mechanism that launches any negative memories to the back of Riley's mind. Riley and her best friends Bree and Grace are invited to a weekend ice hockey camp where Riley hopes to qualify for her school's team, the Firehawks. On the night before the camp, a "Puberty Alarm" sounds off, and a group of mind workers barge into Headquarters to upgrade the emotion console, trashing the place in the process.