Sorry Not Sorry is the ninth episode of Season 32.
Lisa calls her teacher, Ms. Hoover, a hack and refuses to apologize. Then, she learns Ms. Hoover’s private pain.
Homer and Lisa are stargazing on top of the Simpsons' house, Lisa is angry because of what occurred at school with Miss. Hoover the prior week. After a breakfast argument, Lisa shows off her mobile "Who Inspires You?" project. Lisa made a recreation of earth, completely surrounded by satellites. Lisa was inspired by Gladys West, the mathematician who helped create the GPS.
Later, Homer has flashbacks to how the occurrences ruined his chances to avoid Patty and Selma's birthday party three weeks prior, Lisa dreams of being in Yale because of her project. At school kids are presenting their projects, Lisa presents with a report and a statue made of macaroni. Mrs. Hoover is unimpressed, and gives all the kids B- grades. Lisa protests and call Miss. Hoover a "hack". Lisa is sent to detention, where she is protected from bullies by Bart.
At home, Lisa doesn't eat dinner, and hides under her bed. She is companied by Marge, and she encourages Lisa to apologize to Hoover. Later, Miss. Hoover grabs Lisa by the leg, and asked Lisa if she would apologize. When Lisa denied, she was sent back to detention, Lisa is told if she doesn't apologize she can't get into Yale.
The following day, Bart tells Lisa to say "I'm soggy" instead of "I'm sorry". Lisa attempts this stunt, but Miss. Hoover see's past it, and sends Lisa too "Double detention". Lisa proceeds to follow Marge's idea to go to the Springfield Education Annex to learn how she can apologize.
Lisa's consultant suggests to walk a mile in the shoes of the person you'd need to apologize to, Lisa follows Miss. Hoover. Lisa learns how hard it is to live like her, and she has a terrible back problem. She buys Hoover a reclining chair to help Miss. Hoover, but Miss Hoover claims she doesn't accept late apologies.
In the current day, Lisa consults Homer about what she learned that day. and Marge says that she "planted a seed that will grow.", Everyone then comes on the roof to avoid Grandpa. Later at school, Miss Hoover finds a vibrating function of the chair and decides to accept Lisa's apology. She proceeds to gives Lisa and Ralph a B+ for the project. Then at home, Bart continues a word play with Homer but Homer catches on quickly.
Ten years later, Lisa, a student at Yale, finds out her dreams about the annoying singers were true. On top of the roof, Homer dreams of being the Red Baron from Charlie Brown and cries like Charlie Brown once he learns it was just a dream.