Yu/Synopsis

Vs. Queen Bee Arc
As preparation for the Naruhata Festival begins, Makoto brings in Miu and Yu to meet the idol who they'll be performing with, Pop☆Step. After giving a brief introduction, the twins immediately begin gossiping about the vigilante idol and her sense of fashion.

After the East Naruhata High Dance Squad and Mad Hatters arrive, Makoto begins to plan how the groups will be presented on stage. She says that there shouldn't be any problems with the Dance Squad and Mad Hatters, but wonders how to present Pop☆Step and Feathers on stage, since Pop☆Step being in the middle would be the best visual balance but the worst vocal balance, according to Miu and Yu. Makoto agrees, but goes on to state that Pop☆Step definitely has the edge when it comes to stage presence, since Feathers haven't performed in as large of venues as she has. She decides to put the issue on hold and tells Feathers to practice some training drills with the Dance Squad for the time being.

However, during Feathers' training, Miu sprained her ankle, rendering her unable to dance around on stage as it was hoped she'd be able to. Makoto suggests that, if they can't make do, Miu could always be taken out of the performance and Pop☆Step and Yu could perform a duet, to which Miu cries out that she practiced so hard and didn't want to be taken out of the Narufest. After seeing the idol's upset, Pop☆Step says that Miu could always be placed in the center of the stage if her twin, Pop☆Step and the Dance Squad put it enough effort to draw the crowd's attention away from her lack of movement. She smiles at the girls and says that they both need to be there, since they have such talent at singing, and telling them that they should each do that they can.

The day of the Narufest finally arrives, and, after the afternoon portion finishes, Yu and the rest of the performers prepare to go on stage. However, thanks to Teruo Unagisawa, the venue's power suddenly cuts out, leaving it in total darkness and bewildering both the audience and the performers. Captain Celebrity arrives at the venue as he heard they'd been having trouble, and Makoto immediately explains the situation and sends him away to fetch the backup generators. Until Captain Celebrity arrives back and resolves the technical issue, however, the Narufest is deemed on standby.

Just then, Koichi Haimawari arrives back at the venue with Pop☆Step's portable microphone, and the vigilante idol is encouraged by her fellow performers to go on stage and entertain the crowd until the generators arrive. Miu and Yu wish her luck as she heads on stage, and, after a few minutes of her ad-libbing to charm the crowd, the twins smile and remark that, as lame as she was, she was actually kind of cute.

The power is finally turned back on, and Yu takes to the stage with the rest of the performers to perform their remix of the Marukane Department Store jingle, which the crowd greatly enjoys. After the song ends, the crowd goes wild and Miu and Yu are seen hugging with tears in their eyes.

Osaka Incident Arc
One morning in the backstage of Narufest, Miu tells the Sisters of Saint Lila's Academy that there will be a pro hero guest star, but Pop whispers to Miu that Captain Celebrity will not be able to attend today's concert. Miu asks Yu to see if there is anyone in the audience who looks like a pro hero, only to be disappointed that there isn't one.

They make an impromptu decision to have Koichi be the guest star as "The Crawler," who begins singing "Can't Help Loving You," which amuses the three sisters but not enough to forget about the Pro Hero they were promised. Fortunately, Captain Celebrity arrives to defeat a Bat Villain and save Koichi, relieving Yu, Miu and Kazuho as the children got their wish.

One day, Miu notices that Kazuho isn't at practice, and Yu accidentally reveals that Kazuho is heading to Osaka to attend a regional idol collaboration show, making Miu jealous. Yu attempts to calm Miu down as she rants about Koichi's uselessness

Sky Egg Arc
Yu and the rest of the Narufest gang attend a meeting to discuss what kind of merchandise to sell. During the meeting, Miu and Yu suggest selling photos for the fans, but later Koichi passionately advocates for All Might hoodies, confusing and annoying the others. Makoto takes Koichi's idea and makes Captain Celebrity hoodies, disappointing Koichi greatly.

She and her twin sister later attend a Christmas party with Captain Celebrity and the rest of the Narufest gang. After the party, the Sisters of Saint Lila's Academy are kidnapped by a Bomber Villain and rescued by Captain Celebrity, who injures himself in the process. Because of Captain Celebrity's selfless actions, he is allowed to return home and continue working as a hero there. Makoto announces that they will be hosting a farewell party at the Tokyo Sky Egg, featuring numerous Japanese top heroes. Miu, Yu and Kazuho are nervous to be performing in front of thousands of people, but Captain reassures them that they will do great. They begin practicing for the upcoming performance.

On the day of the farewell party, FeatherHATS and the pro heroes start it off with a bang. They continue performing until the Sky Egg is attacked by several Bomber villains. The power is cut off, so the heroes and staff prioritize calming the audience down as well as finding a way to the top of the building to fight the villains. Miu, Yu and Kazuho help by handing out drinks. The crisis is averted thanks to the efforts of Captain Celebrity, Koichi, All Might and the heroes, and Yu continued handing out merchandise and refreshments to the audience members.

The Narufest gang later say their goodbyes to Captain Celebrity at the airport, seeing him and Makoto leave for the United States.

Final Performance Arc
Two years pass by, and Narufest's popularity starts dwindling. At a meeting, they discuss how Makoto has become a global sensation after leaving Japan before getting back to the situation at hand. After getting off track several times, their manager, Rokuro Nomura comes in and apologizes for being late, before breaking the bad news: the next Narufest will be their last. Miu leaves early, admitting that their early successes were thanks to Makoto, saying that maybe it is a good time to end. Yu leaves later for cram school.

Over the next few days, Yu and Miu notice that Kazuho has been arriving late, and they become more suspicious as Nomura leaves with Kazuho one day. One day, they are unable to contact Kazuho or Nomura when they don't attend the meeting. Koichi comes in and is shocked to find out that Pop has been missing out on the meetings more frequently. Miu is infuriated when Koichi tells her that this isn't new behavior for Pop to him, calling him a blockhead, but Yu stops her before the situation could escalate. They decide to confirm her real name and contacts and search for her.

Yu and Miu call Koichi that night, telling him that Kazuho's mother has not seen her daughter since last weekend, and that the police showed up to talk to them. As Koichi heads to talk to the police, Bee☆Pop emerges to wreak havoc on Naruhata. Yu and Miu notice Kazuho bombing parts of the neighborhood and try to talk some sense into her. However, "Kazuho" tells them that causing destruction makes her feel good, before using some Bomb Bees to drop a large billboard on them. Koichi saves Miu from being crushed, though she receives minor injuries in the process.

As Miu recovers in the hospital, Yu is seen comforting her as she is frustrated with Koichi's absence. The Narufest group take shelter at Hopper's Cafe when Bee☆Pop returns to bomb Naruhata. When "Kazuho" starts singing her new single, "Bloom," Yu watches Miu note out how pathetic and desperate her song is.

Naruhata Lockdown Arc
Yu and Miu reunite with the Narufest group at Hopper's Café, where the staff inform them that Kazuho's condition is neither worsening or improving. Yu thanks them for the news while Miu cries tears of frustration. Ichiro Hotta then offers them food, saying it's on the house. That night, everyone is shocked when power is cut out throughout all of Naruhata.