For some reason, Kaguya and Shirogane indulge Fujiwara's idea of doing cosplay for the upcoming gathering with students from their sister school in Paris. Deep down, Kaguya thinks it's silly, but when she puts on cat ears, a subdued "meow" escapes her mouth. Moreover, that minor cosplay is an unexpected major hit with Shirogane, an avowed cat lover. He's so bowled over by her cuteness that he isn't able to maintain his usual presence of mind. The situation becomes more complicated when Shirogane follows suit and puts on cat ears, which secretly thrills Kaguya. Unable to hide their thoughts that each other looks cute, the two act weirder and weirder...

Yu Ishigami is the fourth member of the student council. Despite being a first-year, he was scouted out by Shirogane for his talent with numbers and appointed the council's treasurer. Owing to Yu's introverted personality, he normally doesn't stand out much, but the council would fall apart without him. But one day, Yu goes to Shirogane and confesses his desire to quit the group. In fact, his mind is made up, even though Shirogane desperately tries to persuade him to stay. Apparently, the situation is beyond Yu's control, but with a tear in his eye, he explains to the president that he thinks he's being targeted for murder...

As term-end exams approach, the psychological war between Kaguya and Shirogane in the student council room ramps up. Kaguya is an all-around genius, but her pride is hurt because she hasn't yet beaten Shirogane when it comes to academics. Meanwhile, when it comes to making an effort, Shirogane is second to no one and as the president of student council, he refuses to let anyone else usurp his position at the head of the class. The two of them lie through their teeth and employ wiles worthy of Machiavelli in an attempt to get ahead of the other. At last, it's the day of finals, but which of them will the goddess of victory smile upon?

Half a month into their summer vacation, Kaguya spends her days moping around, unable to see Shirogane without the student council to throw them together. However, she does have plans to see a fireworks display with the other members of the student council toward the end of the break. Kaguya has never been able to make summer memories because of her strict upbringing as the daughter of the head of a financial conglomerate, so she is anticipating the day she can have fun with everyone. But the day before the event, Kaguya's father suddenly summons her home to Kyoto...

After being forced to bail out on seeing fireworks with her fellow student council members, Kaguya shuts herself up in her dark bedroom. Hayasaka, Kaguya's maid, is worried about her mistress's depressive state. She tries to cheer Kaguya up, and when that doesn't work, introduces a plan to sneak out of the family mansion. Kaguya manages to slip past a pair of vigilant butlers and reaches the venue, but the fireworks display is already over. Kaguya is in tears, since she really wanted to see the fireworks with the others, but then she hears a familiar voice: "Then, I'll show them to you."

Kaguya finally gets to go window shopping and watches vigilantly for her chance to befriend Shirogane’s sister, Kei. While the Fujiwara sisters get in the way, she eventually manages to position herself next to Kei. But then, she can only see Shirogane’s resemblance in Kei’s profile, making her heart beat wildly out of control. Kaguya still decides to take the opportunity to figure out what she should give Shirogane for his birthday when Kei mutters that she isn’t very close to her brother. What secrets will Kei spill about Shirogane?

Ishigami has a biased opinion that "Guys who wear boxers are all man whores." Kaguya takes his words to heart and is dying to know what kind of underwear Shirogane is wearing. She tries to come up with different strategies so that she can take a peek at his underwear without it seeming weird, but all her ideas are too naughty. She decides to ask him directly what kind of underwear he likes, but Shirogane misunderstands the question and thinks she is asking him what kind of lingerie he is into. Shirogane starts to imagine the kind of underwear that he wants Kaguya to wear.

Though no one surpasses Shirogane when it comes to academics, his lack of dancing skills finds him in his third intense training session with Fujiwara in preparation for the school sports festival. However, Shirogane is such a hopeless dancer that Fujiwara’s patience runs out and storms out of the room. As Shirogane proceeds to diligently practice on his own, Kaguya appears and starts giving him dance lessons. Fujiwara, who has returned to check on Shirogane, begins to argue with Kaguya about the best way to teach him and so a battle ensues! Who will end up victorious as the better dance teacher?

The student council is asked to model for the Shuchiin Academy brochure. However, Kaguya's family has a strict policy prohibiting her from being photographed for any forms of publicity, and as result, she is unable to participate. As Kaguya longingly observes the rooftop photo shoot, the student council members propose to take a final group photo, solely for private use, on their cell phone, which makes Kaguya very happy. Just then a gust of wind blows across the rooftop, causing her to drop her phone and sending it way down below to the school grounds. Kaguya picks up her shattered cell phone from the floor and begins to reflect on all the photos with everyone she has lost, and becomes overwhelmed with sadness.

What do Shuchiin Academy's model students do outside of their student council duties? These eccentric activities reveal a side of the student council that has never been seen before!

After finally making her long awaited smartphone debut, Kaguya restlessly contemplates over how to respond to Shirogane's LINE message. As Hayasaka watches over, she realizes that Kaguya is not aware of the "read receipt" function. If Kaguya lies by responding that she just read the message, she runs the risk of exposing the truth that she had been obsessively staring at Shirogane's message with glee. Weighing out her options to best serve her mistress, Hayasaka decides to explain LINE's functions when suddenly a new problem emerges.

After their second semester final exams end, there are plans for a sleepover at Kaguya's house. But Shirogane and the others are unable to come, leaving Fujiwara as the only one who can join. While barley glancing at an upset Kaguya, Fujiwara gets excited about the totally hot butler Mr. Herthaka without realizing it's Hayasaka dressed as a man. That night as the girl talk unfolds at the pajama party, a sleep-deprived Kaguya takes on a strange mood before anyone can notice. With that energy, she calls Shirogane and ends up asking outrageous questions.

Shirogane couldn't tell Ms. Herthaka that sometimes humans need to expose their weaknesses and endeavors to practice rapping which should be able to convey that. But his rapping skills are catastrophic. Fujiwara, who previously taught him singing and dancing, tags along for practice. But she's a total amateur when it comes to rap that she's on the level where she's convinced it's all simple-minded puns. So Fujiwara begins special training. With the advice from Shirogane who has overflowing knowledge on rap music, she rapidly improves... But something is still missing!

Kaguya learns about the romantic legend that giving a heart-shaped gift at the Culture Festival brings eternal love. She wonders if there is a way she can give Shirogane a heart-shaped gift without getting caught. But her plans are full of errors, and she panics. She becomes sick of herself as a cowardly person who can only come up with negative ideas. There, Shirogane, exhausted from preparing for the Culture Festival, shows up. As Kaguya sees Shirogane doing his best for everyone as the student council president, she...

Shroud in a cape and dressed in the guise of the phantom thief Arsène, Shirogane waited for Kaguya's arrival atop the clock tower roof overlooking Shuchiin. When asked why he would do such a thing, Shirogane answered that there was something he wanted to show Kaguya. The festival's afterparty has already begun as the sun set over this school and the students could be seen encircling and enjoying the bonfire. While the emotions that could not be expressed with words mingled between Shirogane and Kaguya's hearts... Shirogane carried out his ultra-romantic operation!!