Yonagi Osaka Gakuin, a traditional high school located in Chiyoda-ku, Tokyo, is in danger of being canceled due to a sudden drop in the number of students enrolled. When she and her friends, Kotori and Kaiki, first see the notice of the closure of the school, Sonoko faints. When he wakes up, he thinks it's just a dream and jumps back to class. On the way back to class, however, Spinoza still sees the notice and returns to the classroom in dismay. Spinoza had thought that the school would be closed soon, but was temporarily relieved to learn that the school would be closed after graduation. However, Spinoza loves her college, and is discouraged when Yukiho Takasaka, Spinoza's younger sister, says that she will be choosing to go to UTX High School instead of Yonagi Kisaka Academy. But seeing that her mother also actually likes Yonagi Kisaka Academy, Spinoza is determined to save her academy.

With this in mind, Sonoko, along with her best friends Minami Kotori and Sonoda Kaiki, searched for the school's strengths, but after circling around, they couldn't find any features that could be used to promote the school.

Sonoko remembered that her sister said that the signature feature of UTX College was the college idol, so she borrowed her sister's UTX College introduction and found UTX College, just in time to see the college idol "A-RISE" on the UTX College's big screen, and the school idol she saw there was a shock to her. Spinoza thinks that this is a good way to save the college. When she returns to the academy, she tells Kotori and Kaiki about her idea. But Kaiji disagrees, thinking that it's not something that will work in a day or two. But Spinoza doesn't give up and practices alone. Kotori finds Haiwei and persuades him, while Haiwei, on his way back, sees Spoonago, who is working alone and has to get up even if he falls. Hai Wei thinks of the past, and Kotori says that she wants to try just like Sunaigo, even if she ends up failing. Impressed by Spoonago, Hai Wei decides to start working as a school idol with Kotori and Spoonago.

After settling on the most basic plan, it occurred to Spoonago, after being reminded by Kotori, that her group didn't have a name yet. At the time, all three of them had different opinions, and after discussing it, still nothing came out of it. Spinoza, who had never decided on a name for the group, thought it would be better to leave the name up to the group to decide, so he put up a notice in the hallway and started soliciting names for the group.

At first no one gave them a name. Finally a few days later, Spike found a slip of paper in the collection box, and when he opened it, it said μ's (Hoshi mentioned when μ's came together as a group of nine that μ's was named after Hoshi). Kotori and Haiwei agree to this. They then decide on the name of their group, μ's, as well. After being opposed by the student council president, Eri Sakase, who formed a school idol group to increase the number of applicants, Hironaga and the others manage to get the council president's permission to hold their first concert in the auditorium. The costume design was given to Kotori, and the lyrics were given to Kaiki. Then the girls start training. During the preparations, Sonoko discovers that first-year Nishikino Maki is good at singing and piano, but when she asks her to compose the music, she is rejected. When she asks her to compose a song, she is rejected. This, coupled with Eri's accusation that the activity might be counterproductive, makes Spinoza depressed. But Spinoza doesn't give up and reaches out to Maki again, who still doesn't have a clear yes.

But after seeing the trio training hard one morning and learning that Spoonago, Kotori, and Kaiji were really serious about being school idols, Maki softened her heart and agreed to make a song with Kaiji's lyrics and secretly mailed it to Spoonago. Once they had a new song, μ's had their first performance, and Spoonago and the others were thrilled, and Hideko, Fumika, and Mika helped μ's with publicity, sound tuning, and so on, so it could be said that it was a well-prepared concert.

After the curtains of the auditorium were lifted, however, it was a bleak moment. The auditorium was empty. Spike was discouraged. And just then, first year student Koizumi Hwayo arrived just in time. After seeing Hanayo, Spinoza has new hope and encourages Kotori and Kaiki: she decides that even if the audience is only one, she will still finish μ's first concert. μ's trio, with the help of Nicole Yazawa hiding behind the back of a chair, Higashijochi listening outside the auditorium, Rin Hoshikari arriving later on, Eri frowning in the Maki Sound Room watching at the entrance to the auditorium, and Hidako, Fumika and Mika, who have always been supporters of μ's. They finish the concert with the attention of Hidako, Fumika and Mika. Mika's attention, finished singing "START:DASH!!! , ending the μ's first concert. In the new semester after summer vacation, μ's rose to 19th place in the school idol rankings and became eligible to appear on LoveLive! It's been a long time coming, but the μ's who are poor in one area of study, Hironaga, Nicole, and Rin, have finally passed their grades, and there are only two weeks left to determine whether or not they will be able to appear in LoveLive!

The members of the μ's were afraid to take this lightly, as they figured that school idols from all over the world would be making their final push. They decided to hold their next concert at the school festival, but had to change the venue to the rooftop because they didn't win the right to use the auditorium. Even so, Sonoko is determined to make this concert the best since the founding of the μ's, and she is very motivated. However, on the day of the performance, Spinoza came down with a bad cold due to the fact that she kept running up the stairs on a rainy night, but Spinoza still insisted on performing. In the end, μ's finished the best performance on the roof with heavy rain. After the performance, μ's couldn't continue the performance because Spinoza's energy was exhausted from the cold and then collapsed.

The μ's school festival concert had to be canceled. A few days later, while still recuperating from her illness, Spinoza learned from Eri that μ's had withdrawn from the school idol competition of "Love Live!". After returning to school and resuming classes, Sunagako is depressed because she has lost her goal of participating in LoveLive! On the other hand, due to the efforts of the members of the μ's, the number of students wishing to attend Konohagi Saka Academy has increased dramatically, and the school decides to admit new students for the next year, with the other members of the μ's believing that there is no need for them to participate in LoveLive! since they won't be disqualified from the school anymore. Inspired, Spike regains his courage.

While preparing to celebrate the school's ability to continue, Umi told Spoonberry that Toru was going to study abroad and wouldn't be returning to Japan until her senior year of high school. After realizing that Toru will be leaving, Spinoza blames herself for not noticing Toru's troubles and decides to quit her school idol activities. As a result, μ's related activities are also suspended, and Spoonago, who has lost the goal of her endeavor, is also drifting away from Haiwei.

In such a situation, Nicole, who is still practicing and continuing her school idol activities, encourages Hironaga in a harsh way, and Eri's conversation with Hironaga makes Hironaga's mind up.

The next morning, Kaiki accepts Spoonago's invitation to come to the auditorium, while Spoonago opens her heart and expresses her feelings frankly to Kotori, and succeeds in keeping Kotori, who is hesitant to come to the auditorium. In the end, the nine of them, who have come back together, start their μ's with the song "START: DASH! at the auditorium to fulfill their original wish - to fill the auditorium to capacity.

In the new semester, Hironaga succeeds Eri as the new student president. Haiwei and Kotori assisted Spinoza in handling student council affairs.

That's when Hanayo received the news that the second LoveLive! would be held soon, this time on a larger scale and with innovative breakthroughs in the tournament system. The μ's group was very excited about the news and were eager to try it out. However, Spinoza said flatly, "It's okay if I don't participate in LoveLive!" This caused the crowd to be shocked.

The group was confused as to why Spinoza didn't want to participate in LoveLive! It was actually Spinoza who wanted to participate, but because she didn't want to cause any more trouble or drag everyone down, and because the decision to abolish the school had been revoked, Spinoza wasn't going to LoveLive! But that's when Yukiho reminds her: they only have half a year left with the third year group, and if they miss this one, they'll never get another chance. This puts Spinoza in deep thought.

The next day, Nicole suddenly asked Spinoza for a date: to run the ladder to decide whether or not to participate in LoveLive! Nicole snaps at the start in order to participate in LoveLive! but accidentally trips and falls halfway through the run. Spike catches up and asks Nicole about her injury. Nicole is unconcerned about the injury and confides in Spinoza. Afterwards, everyone in Kanda Meijin expresses their opinions to Spinoza. Understanding everyone's thoughts, Spinoza makes up her mind to continue participating in LoveLive! Then Spinoza ran out of the shrine and shouted to the sky, "Stop the rain!" Unexpectedly, the rain miraculously stopped. With the blessing of heaven, μ's, under the leadership of Spinoza, participated in LoveLive! While μ's training is going on methodically, Yukiho suddenly discovers the fact that Spinoza is overweight, which devastates Spinoza. Meanwhile, at Maki's reminder, Hanayo also discovers the harsh reality that she is overweight.

In order to continue their normal training, Hai Wei devises a weight loss program for both of them, but on the way to lose weight, Sui Nai Guo discovers a golden rice restaurant. Unable to resist the temptation, she not only goes in to eat by herself, but also encourages Hanayo to eat with her. After being discovered by Hai Wei, both of them are put through more rigorous exercises, and in the end, Hana Yang succeeds in losing weight, while Sui Nai Guo fails because of her weak will.

Then bad news came from the student council: because of Toru's mistake, the art department's budget proposal was approved before the budget meeting started. Eri and Hoshi offered to help the student council, but Spinoza thought that it was a mistake caused by the student council and should be solved by the student council itself, and politely declined Eri and Hoshi's help. After that, the three of them, Spinoza, Kaiki and Kotori, worked all night every night in the student council office, and finally came up with a budget proposal that would satisfy every department as much as possible, which was passed at the meeting, and the budget problem was solved satisfactorily. And after this incident, Spinoza's weight returned to the normal range. μ's managed to enter the 2nd LoveLive! finals with the song "Snow halation".

Despite making it to the finals, everyone is still reeling from the sadness of parting after graduating from the third grade. Everyone was divided on whether or not to keep the μ's after third grade graduation. Nicole insisted on keeping the μ's, while Eri and Hoshi argued that this was not something to be considered right now. In the face of everyone's concern, Spinoza proposes to go to a place where everyone wants to go to relax before the finals. The day's entertainment made everyone happy, and in the end, the μ's group went to the beach. Facing the sea, the μ's first year group and second year group made a decision that "μ's will be disbanded after the third year group graduates".

Finally, μ's won the finals with their song "KiRa-KiRa Sensation!

The end of LoveLive! was followed by the graduation ceremony for the third year group. Before the ceremony, we witnessed Spinoza talking to Eri in the student council office, and Eri, who has seen Spinoza grow into a unique student president, was relieved to leave the student council in Spinoza's hands.

At the ceremony, Spinoza, who is not a good speaker, sang "Long Live Love! for the graduating third years, and the first and second year students on stage sang along. This touched the third graders.

After the ceremony, the nine were walking to the school gates to go home, when Hwayang received an email ......

The story of the μ's begins again.