Akane Tachibana reports the first year's first Special Test results to Manabu Horikita. Back on the cruise, Yosuke Hirata asks Kiyotaka to accompany him to lunch, but the latter refuses after mentioning Kei Karuizawa. The first years are informed of a second Special Test -- each student is to meet at a rendezvous point at a certain time. Including himself, Kiyotaka's rendezvous consists of Kei and classmates Hideo Sotomura and Teruhiko Yukimura; there, an instructor explains the Special Test.

The students are split into eight groups of 14, with three students from Classes A and B and four from Classes C and D, and each group under the name of a planet. The test is three days long, and at 8:00 am on the first day, the school declares a member of the group a "VIP," and the group discusses who the VIP is twice a day. After 30 minutes of the final day, everyone but the VIP sends a guess to the school. There are four cases of the test. Case 1: if everyone but the VIP's classmates sends the correct answer, each student will receive 500,000 private points and the VIP an extra 500,000. Case 2: if at least one person -- excluding the VIP's classmates -- sends a wrong answer, the VIP receives 500,000 private points. The remaining two cases apply if the VIP is exposed before the end of the test. Case 3: if a student sends the correct answer, they will receive 500,000 private points, their class will earn 50 class points, and the testing period is over for the group. Additionally, if the VIP's classmate sends the correct answer, it will be deemed invalid, and the test will continue. Case 4: if a student sends a wrong answer, their class will lose 50 class points, the VIP will receive 500,000 private points, and their class will receive 50 class points, and the testing period is concluded. Additionally, if the VIP's classmate sends a wrong answer, it will be deemed invalid, and the test will continue.

Hirata receives information from someone that Kikyo Kushida is a VIP, which he tells to Yukimura and Kiyotaka. Rokusuke Koenji presumably discovers the true VIP, and as a result, the Jupiter group's test has been concluded. Suzune is upset that Koenji made a reckless move, and she and Kiyotaka decide to unite Class-D to get the most class points. To do that, they decide to use Kei as a primary player since she has a powerful presence amongst the Class-D girls. Still, Kiyotaka notes that Kei has been unusually passive compared to her normal arrogant attitude. Ryuen once again shows up and declares his intent to win the test. He convinced his classmates to give in their phones, so he'll receive the results; he left after proposing that Classes B, C, and D should unite to take down Class-A, which Suzune refused. Elsewhere, Kei is recovering from her breakdown and refers to herself as a "parasite" as she is codependent on others. Kiyotaka and Kikyo find each other, and she leaves after abashedly hugging him. Chie Hoshinomiya, the Class-B teacher, asks Sae Chabashira, the Class-D teacher, how Kiyotaka became the leader as the Island test ended, to which Sae doesn't answer.

Yukimura and Kiyotaka finally intervene in the situation, but Kei chides them. On the third day, the Venus group's test has concluded; thinking that Class-C is trying to exploit the test, Kiyotaka sends an email to Shiho. Kei is lured to a secluded part of the ship when Shiho and her girls, along with their classmate Rika, show up. Shiho infers that Kei was bullied before, confirmed when Kei had a panic attack. Shiho coerces Rika into relentlessly slapping Kei while Kiyotaka watches-- revealing that his email to Shiho was about Kei. After the girls leave, Kiyotaka approaches the crying Kei and berates her current self; Kei talks about the experience of abuse. Kiyotaka finds a wound on her chest; upon seeing that, he vows to protect her in exchange for working with him to unite Class-D to win the test. Afterwards, Kiyotaka goes to Sae to buy something with his points.

The VIPs were chosen based on their name's position in the Hiragana scripture and the corresponding planet group of said VIP. Class-D talks about how Class-C is not fully united. The school will hold a 13-event Sports Festival with the theme of Team Red vs Team White -- Team Red consists of Classes A and D, and Team White consists of Classes B and C. The Sports Festival has several merits (the top three placements have a choice between 1,000 private points or bonuses on their written exam) and demerits (the bottom ten placements lose bonuses on their written exam), and classes can decide participants for the events. Kiyotaka and Suzune discuss that strict preparation separates the Sports Festival from the previous two special tests; Suzune wants to win by "unfair" methods, but Kiyotaka believes they can win by "normal" methods. Later, the class decides on choosing participants through skill or volunteering; Suzune suggests that they should pair stronger and weaker students to win the events, at the risk of the weaker students losing out on merits. Kei disagrees with Suzune's proposal.

Kiyotaka and Suzune speculate that Kikyo is betraying the class because she's receiving private points from other classes. The three of them go surveilling Team White, much to Kikyo's chagrin that Suzune's present; Suzune blatantly asks if Kikyo did sell her VIP information, to which Kikyo denies and asks to trust her. The Sports Festival begins. Ken Sudo motivates Class-D, while Arisu Sakayanagi of Class-A observes the Festival. When Koenji drops out, Sudo lowers the class morale. Team Red loses the "Topple the Pole" event when Ryuen beats down Sudo; things get worse when Suzune gets injured after colliding with Class-C's Saki Kinoshita. After failing to convince Koenji to rejoin, Suzune wishes that she had Kikyo's natural charisma and admits she liked her at some point. Team White continues targeting Sudo and Suzune, continuing to lower the Class-D morale.

Suzune tries to convince Sudo to rejoin but ends up scolding him after he refuses to. Sudo admits that he joined the Festival for attention and to get back at those talking bad about him; Suzune affirms that he mustn't give up and keep fighting, or he'll be worthless and will await his return. Before the break ends, Kiyotaka confronts Kikyo about her being the traitor. She initially denies the accusation but poses a notion as to why Kiyotaka didn't change the list if he knew she leaked the participation list, which she deduces would've caused inter-class confusion. She finally reveals that she is the traitor for leaking the list and selling her VIP information to Ryuen for her desire to see Suzune and Kiyotaka expelled. Suzune tries to convince Sudo one more time, talking about how they are the same in seeking acknowledgment from others. She talks about how she has always been seeking acknowledgment from her brother, outcasting herself from others to reach it; after going through her experiences with Class-D, she realizes that she can't fight alone and needs allies, which Sudo gives in after being moved by her words.

Sudo rejoins the Festival and apologizes for his actions earlier. Suzune and a male student drops out of the final event, so Kikyo and Kiyotaka step in for them. For the final event -- a relay race -- Manabu and Kiyotaka talk about the statuses and future of Class-D, and the latter indulges the former in a race to learn more about him. As soon as Kiyotaka receives his baton, the two laps all the runners and run at dead heat, leaving the school in awe. At the end of the festival, Class-D ends up coming in last but praises Kiyotaka for his performance. Suzune talks about how she has personally grown and affirms her belief in helping Class-D become strong, which shocks Kiyotaka.

Manabu Horikita announces his resignation as the Student Council president. In his place will be Miyabi Nagumo from Class 2-A, who plans to change the school into a meritocracy. After the assembly, Kohei Katsuragi from 1-A advises Kiyotaka, Suzune, and Class-D to be wary of Ryuen. After he leaves, Maya Sato from 1-D bashfully asks Kiyotaka to exchange their numbers and implies she has a crush on him. Despite Class-D coming last for the Festival, none of the students were expelled, much to Ms. Chabashira's surprise and content. She then lets the class know about the next Special Test, which will serve as their final exam: Paper Shuffle.

Two students will be paired up and must score above 60 points as a pair -- even if X student scores 0 and Y student scores 60 -- or both students will be expelled. The pairs will be determined through a mini-test, and there is a threshold for the total points from all subjects. Each class will make questions for the exam, which will be answered by one of the other three classes; the class that made the questions can request other classes to do the test, and there will be a lottery in the event of a double request. The requestee and the requestor will go head-to-head, and whichever class scores higher will steal 50 class points from the other. Cheating will result in immediate expulsion.

Suzune and Kiyotaka suggest preparing the class for Paper Shuffle. Kei and Kiyotaka exchange emails about her witnessing Maya's confession; Kei, Hirata, and Sudo join Suzune and Kiyotaka to prep for the exam. Kikyo asks to join in, much to Kiyotaka's suspicion; he and Suzune plan to rejoin the others as they leave to prep, as she prepares to tell him about Kikyo's past.

Kikyo reminisces her thoughts on the aftermath of the class implosion. Class-D will have study sessions for Paper Shuffle, with Kikyo and Suzune as overseers. Kikyo rushes out of class as she receives an email. Yukimura offers to oversee a pair for Paper Shuffle -- Akito Miyake and Haruka Hasebe -- noting that unity and cooperation are necessary to win; Suzune asks Kiyotaka to join Yukimura's group to track progress. At Yukimura's study session, the students encourage Kiyotaka to stop holding back -- given his performance at the Festival. Kiyotaka advises preparing for any dirty tricks the classes make for the exam, noting that the school might have a system to mediate questions. Later that same day, Kiyotaka relays that information to Suzune as the two discuss keeping an eye on Kikyo by inviting him to oversee Suzune's group. Kiyotaka receives an email from Ryuen asking who's the mastermind of Class-D.

At Suzune's study session, the kids tease Maya and Kiyotaka; afterwards, Suzune meets with Kikyo alone. The two make a bet for the Math exam of Paper Shuffle: if Suzune scores higher, Kikyo will stop messing with her; otherwise, if Kikyo wins, Suzune will get expelled. To acknowledge it as a real bet, Suzune gets her brother to witness the agreement. After he leaves, Kikyo senses that Kiyotaka is on a call with Suzune and asks him to meet with her. At the meetup, Kikyo adds another condition that if she wins, Kiyotaka will get expelled, to which he agrees; by agreeing, he wants to know about Kikyo's past to see why she is the way she is and get the whole picture, to which Kikyo complies.

As a child, Kikyo was praised for being a top achiever, so much so that she craved praise and attention, which eventually stopped. She then decided to become the nicest, friendliest, and most caring person, so that others could rely on her and gain everyone's trust. This eventually took a toll on her mentally, despite continuing to put up a front. To combat her distress, she created a personal blog wherein she gossiped about her classmates. On that fateful day, her classmates found her blog and shunned her; tired of keeping up a front, she revealed every dirty secret of all her classmates, which eventually turned the class against themselves and imploded.

Kikyo informs Ryuen of her bet with Kiyotaka and Suzune; in exchange for their expulsion, Kikyo will let Class-C win Paper Shuffle. Later, Ryuen intrudes on Kiyotaka's study session and vaguely asks about the email to fish out the Class-D mastermind. A Class-C student, Hiyori Shiina, notes that Kiyotaka and Yukimura have forgettable faces. Thus, she isn't sure if they are the mastermind. Feeling comfortable with the study group, Haruka decides to make a friend group where they share their names with Akito, Kiyotaka, and Yukimura -- who asks to be called Keisei; Airi joins the group as well, dubbed the "Ayanokoji Group." Later that night, Kiyotaka calls Kei to play an important part for Paper Shuffle, which she agrees to do so, then sends a birthday wish to him.

Every student passed Paper Shuffle. While witnessing Honami Ichinose and Arisu Sakayanagi hang out, the Ayanokoji group notes that everything about Honami is perfect, which they find unsettling; to take down Class-C, they decide to target Honami. A Class-C student follows Kei around. Later that night, Kei lets Kiyotaka know of the incident and also lets him know that a Class-A student was spying on their study sessions. The next day, many Class-D students are being provoked by Class-C; Suzune notes that Ryuen is doing this to exploit the mastermind and that he isn't buying into her being said mastermind. While returning Suzune's book to the library, Kiyotaka sees Hiyori from Class-C and the two talk about books they like despite being in rival classes. Afterwards, Kiyotaka is taken to a reception room where his father awaits, whom he hasn't seen in a year and a half.

Kei recounts the conversation from the night before. Ryuen intrudes on Class-D; Koenji leaves class, with Ryuen and his men giving chase, making Class-D concerned. In the courtyard, Koenji is confronted by many Class-C students as Ryuen starts instigating by breaking Koenji's property. Arisu and some Class-A arrive to witness the altercation. Koenji infers that Ryuen is seeking the Class-D mastermind and defuses the situation by claiming that he has no interest in the inter-class war and will do whatever he wants. Ryuen subsides his aggravation, but Arisu gaslights him by teasing him, upon which, Ryuen goes to kick her, only for a Class-A student, Hashimoto, to defend her. As everyone leaves, Ryuen threatens Suzune and Class-D and declares his search for the mastermind is concluding.

Ryuen continues torturing Kei, saying that the mastermind abandoned her. He claims that the mastermind set Kei up during the Special Test on the ship, when she was lured to a secluded part wherein Shiho and Rika bullied her; Kei nearly gave in to revealing Kiyotaka, but keeps her composure, upon which Ryuen threatened to expose her past bullying, to which she accepts if it means helping Kiyotaka. Realizing something's wrong, Kiyotaka bails on the karaoke plan and instead goes to Ms. Chabashira, asking her to stop Ryuen from harming Kei for Class-D to advance; she agrees after Kiyotaka enlisted the help of Manabu to "eliminate" Ryuen in exchange for Suzune joining the student council. Kiyotaka arrives at the gymnasium to save Kei, revealing himself as the mastermind, much to everyone's surprise.

After losing to Kiyotaka, Ryuen rethinks his decisions, which Mio is displeased with, given that he became docile. Kei is shocked that her feelings for Kiyotaka have grown stronger. Maya tells Kei that she's confessing to Kiyotaka in two days, on Christmas day, much to the latter's confusion, given her feelings for him; her confusion is further proven after he calls about things to know about Maya later that night. The next day, Kiyotaka lets Suzune know that her brother wishes for her to join the student council and believes it will benefit her later. Later that same day, Kiyotaka and Ryuen meet and the two talk about how the former saved the latter by Class-D taking part in the responsibility for the gymnasium incident. Kiyotaka will continue to observe Class-D's process to ascension and reveals his prediction of Class-D reaching Class-C and then getting demoted due to his intention to expel Kikyo the following term.

On Christmas day, Kiyotaka and Maya meet, with Kei and Hirata accompanying them as a double date. The four watch a movie and then go for lunch; after Kei and Hirata leave, Maya confesses to Kiyotaka, and he turns her down due to never having romantic feelings for anyone. A dejected Maya walks away as Kei witnesses the rejection and asks if he views everyone as tools for his benefit, to which he neither confirms nor denies it. Kei gives him a present, to which Kiyotaka reciprocates by giving her cold medicine; as the two head back, he calls her by her given name for the first time and ponders how she's a good pawn but whether he'll ever stop thinking of others as such.