Riley and Maya are anxious to begin eighth grade and have a new teacher who isn't Riley's father. Meanwhile, Mrs. Svorski asks Topanga to take over the bakery.
The students of John Quincy Adams Middle School are curious to know of status of Riley and Lucas's relationship, which ultimately confuses the two of them more than ever before.
When the entire class gets detention, the class divides and chaos ensues. Meanwhile, Auggie's friend Ava attempts to be nicer when she thinks she's losing him to another girl.
Cory and Shawn take the girls out for a fun night, but just as Maya feels closer to Shawn, someone from his past comes back into his life and risks ruining everything.
Uncle Eric is recruited to run for the Senate, but learns it was only because they expected him to lose. Riley and her friends rally together to help his campaign.
A new teacher is hired and uses non-traditional ways of learning to engage the students, and the principal does not agree. Cory defends the teacher, which ultimately gets him in trouble too.
Riley is asked to the semi-formal dance by a classmate named Charlie and is torn whether to go with him or Lucas. Meanwhile, Cory's brother Eric is paid a visit from an old friend, Jack Hunter.
Riley, Maya and Lucas emphasize the beauty of being unique as they rally around their friend Farkle Minkus, who may be on the autism spectrum. Meanwhile, his friendship with another student, Smackle, grows fonder.
When Riley comes to the realization that her parents, Cory and Topanga, are making a positive impact in the world, she questions the impact she's making to the world.
After Maya hurts Riley's feelings, the group learns that Riley is overly sensitive because another classmate is making fun of her. Riley's friends encourage her to like herself for who she is.
Mr. Matthews decides to do something different, so he gives the class the forgiveness project. Everyone else finds it easier to forgive somebody except Maya - she has to choose if she should forgive her absent dad or fail.
Maya and Farkle are caught cheating on a test and have to face the school honor board. Meanwhile, Auggie tries to figure out what he wants to be when he grows up.
With middle school graduation around the corner, Riley, Maya, Lucas and Farkle work together to determine what kind of legacy they want to leave at John Quincy Adams.