Despite not making it to the nationals, the girls become eager to enter the next Love Live! event taking place next spring. As the girls prepare to hold a concert at a school open house, Mari is perturbed by a phone call from her father, something Kanan and Dia are quick to pick up on. Mari eventually reveals to the others that, despite her attempts to overturn her father's decision, the school open house will be cancelled as it has been decided Uranohoshi High will officially stop accepting new students and be closed down. As Chika is initially hit hard by this news, she remains determined not to give up and make a miracle happen, a sentiment that is quickly met by the rest of Aqours.
Given the task of recruiting a hundred prospective students by the end of the year to save the school, the girls split into groups to write new songs for the next Love Live qualifiers. However, the first and third years struggle to work together due to their differing taste in music genres. Feeling the trouble lies in the girls not knowing each other well enough, Dia tries having them do activities together, but that also leads of a conflict of different tastes. As the girls take shelter from the rain in a Buddhist temple, a leaky ceiling leads to a moment of inspiration, allowing them to bring their differences together and finish their song.
Mari gets word that the school open house has been postponed by a week due to road repairs, putting the event on the same day as the Love Live qualifiers. With their only way of attending both events seemingly foiled after a failed attempt at being chosen first to perform at Love Live, the girls are left with the tough decision of either choosing one event over the other or splitting their group between them. Thanks to a moment of inspiration from Chika, however, all the girls manage to perform at the qualifiers before using a monorail used for delivering mandarins to reach the open house on time.
After passing the Love Live qualifiers, the girls realize that they are short on cash for their activities and start looking for ways to raise some money. Meanwhile, Dia becomes uneasy with how Kanan and Mari are close with the others and looks for ways to get more personal with them to no avail, even after some counseling with her third year friends. During a part-time job at the local aquarium, some children start making a ruckus until Dia steps in to calm them down. Once Kanan and Mari reveal to the others Dia's intentions, they approach her and reveal that they admire her mature, responsible self, and that she does not need to change for their sake.
Coming across a stray dog, Yoshiko, whose home doesn't allow pets, asks Riko to look after it. Despite Riko's fear of dogs, both she and Yoshiko grow attached to the dog, but inevitably have to return it to its rightful owner. Unwilling to accept the circumstances, Yoshiko stakes out the owner's house in the hopes of seeing the dog, with Riko deciding to accompany her. After getting to see the dog, Yoshiko accepts that it belongs with its owner while Riko manages to bridge the gap between her and Chika's dog.
The girls learn that there are only 57 prospective students so far and the deadline for attaining 100 needed students will coincide with the regional qualifiers, which will be held at the same place from the last time. As Kanan reminisces about the special routine she developed two years ago that led to Mari's injury, Mari and Dia convince her to let Chika try it, as they have only one chance left at Love Live. Chika spends two weeks trying to learn the routine without success, until Kanan convinces her that she must give up on it should she not manage to do it the next morning. She then spends the entire night practicing, later joined by the rest of Aqours, who thank her for gathering them together. As the sun rises, Chika finally manages to perform the routine, which she does perfectly as they perform in the regional qualifiers.
Aqours manages to qualify for the Love Live finals, but the school remains short of reaching its target, with Mari's father giving the girls until the next morning before the application page is shut down. Unable to do anything more than they already have, the girls stay overnight at school to watch the numbers until the last minute, only for it to fall just short at 98 applicants. With Uranohoshi's merger now a certainty, the girls, noticing Chika has been hit particularly hard by the result, decide to think over whether they should still perform at the Love Live finals now that they can no longer save the school. The next day, Chika remains in denial, but is encouraged by her classmates to win Love Live and immortalize Uranohoshi as part of its history.
The girls are invited to Hakodate to attend the Hokkaido Love Live regionals, where Saint Snow are competing. However, Saint Snow end up making a mistake in their performance and fail to qualify for the finals. The next day, the girls tour come across a restaurant where Leah and Sarah work, with Leah stating she no longer wants to be a school idol. Noticing that Leah had been crying, Ruby identifies with her fears they she will no longer be able to perform with their respective older sisters. After speaking with Dia, Ruby goes to see Leah and proposes that they both perform a song dedicated to Dia and Sarah as part of a Christmas festival.
With Yoshiko and Hanamaru's support, Ruby and Leah create a song dedicated to their sisters in order to show them that they'll be okay without them after they graduate.
Now that their school life is coming to an end, Kanan, Dia, and Mari decide to go search for a shooting star like they did when they were kids.
Following requests from some of the students, Mari agrees to hold a "school closing festival" for Uranohoshi. However, preparations are set back after Shiitake sneaks into the school and causes damage, so everyone stays up late to get things ready for the next day. As the festival gets underway, Chika checks out the various attractions, which includes her classmates arranging a balloon display for everyone. At the end of the festival, Mari almosts breaks down in tears of regret, but is cheered up by cheers of support for Aquors.
The day before the Love Live finals, the members of Aqours head out to Tokyo to perform for the last time. Will they be victorious?