Arisu Sakayanagi

Appearance
Arisu is a petite teenage girl with lilac colored hair and violet eyes. She wears a black beret on her head with a gray ribbon connected to it and wears the standard school uniform.

She often walks with a cane due to her health condition and she is quite short for her age when comparing to other classmates due to her at birth. Many people in the school finds her cute but are afraid to approach her due to the power and dominion she wields.

Personality
Arisu appears to possess a "go with the flow" attitude as she accepts most situations without protest or complaints. Although she does openly voice her dislike of boring situations after Kōhei Katsuragi (Arisu's classmate) spoke about the class scores. Unlike Katsuragi, who has a conservative stance, Arisu possesses an innovative outlook on things. Together, the pair effectively lead Class A through the school years. In the eyes of her schoolmates, she is considered to be someone who stands out from the rest and that no one has ever seen her lose her composure. Truthfully, she is just like any normal girl and the only one who was allowed and seen her act that way was Kiyotaka Ayanokōji.

She enjoys situations she finds interesting as shown when she smiled at Kakeru Ryūen's declaration to rule the school or when she listened to the speech of Suzune Horikita.

In the light novels, Arisu enjoys toying with people, as seen when she cryptically hinted that she knew Kiyotaka Ayanokōji, whereas he doesn't remember meeting her before. Later on, while being together with Honami Ichinose, she also appeared to be very confident and complacent after Teruhiko Yukimura of Ayanokōji Group boldly claimed that D-Class has a plan to overtake A-Class soon. She always carries an aura of imperturbability and seems like a wiseacre whenever anyone is in her presence. Although her soft tone could effortlessly make people feel comfortable around her.

Additionally, although she has an easygoing personality, it was shown in the latter part of the series that she is easily provoked when being described based on her petite appearance (e.g. "Little Girl"), as she believes that it does not give her justice, due to her domineering qualities. She may come off as egotistical and arrogant towards onlookers, however this is also a frequent use of one of her tactics to establish control over the minds of those she chosen. She also holds grudges but doesn’t exhibit them on the outside. After Yamauchi made her fall and made a crude comment about her, she pretended that it didn’t affect her before plotting and executing his expulsion by pretending she was interested in him.

She blatantly told Ichika Amasawa that she doesn’t view her as a threat and that she views her as a failure when compared to Kiyotaka. The latter successfully recognises that she is trying to agitate her and retaliated by accepting her challenge before walking away. In truth, Arisu finds her extremely dangerous and couldn’t afford to allow her to run free which prompted her to reign her in before she does something detrimental.

Background
Since her childhood, Arisu always believed that their potential is set to stone the moment a person is born into the world. It is nothing but just pure luck. A child can't do more than what's carved in their DNA. In other words, if one wants to create a genius, one must do it at the genetic level. A child with superior DNA will always be on the top. After visiting the White Room with her father, Chairman Sakayanagi, she found that one child in the facility was outsmarting everyone else in chess, overwhelmingly defeating his opponents, one after the next. Among the children, he was the only one snatching away Arisu's gaze and heart. According to her father, his name was Kiyotaka Ayanokōji, the son of the person running the facility. Arisu then decided to smash him, and everyone else present there to prove to her father that talent is not decided by education, but from the moment people are born. She who had superior DNA could never lose to the children from that facility.

Plot
Arisu is introduced in the anime when she and Kōhei Katsuragi were being talked to by the Student Council President about the school system.

After a while, she is seen next to Katsuragi in the hallway while observing the class points for each class. She then proceeded by commenting on how things gets very boring due to seemingly no struggle between the groups.

One day, while out in the rain she and her followers met Kakeru Ryūen and his followers. While her group protectively surrounds her, she stops them. Ryūen then remarked on how it looked like that she had established her rule in the school very quickly and only in a manner of weeks. He swore to her that he will take down all the classes including hers at the end so that he would be the one to rule the school. She simply smiled at his declaration, sardonically remarking of how he was going to make things fun and interesting for her, before agreeing with his previous statement of her accomplishment.

Volume 5
In the light novel, Arisu made her debut in Volume 5.

After Ayanokōji's remarkable performance in the final event- Relay in the Sports Festival, Sakayanagi asks Class A Masumi Kamuroto bring Ayanokōji to the 3rd floor of the special building, where there was no surveillance camera installed. The girl then heads towards a corner and asks whether she can go now. Sakayanagi praises her for her excellent work and says that she would rely on her again in the future. The girl (Masumi Kamuro) nods and leaves Sakayanagi with Ayanokōji. For a moment, both Sakayanagi and Ayanokōji simply stare at each other. She then mentions the relay race, to which Ayanokōji asks her to let him send a mail first next time. After that, Ayanokōji asks if Arisu Sakayanagi is the one who called him out, to which she confirms.

Arisu : "After seeing you run, I remembered something. I called you here because I wanted to share the shock I felt with you. It’s almost like the buildup toward a romantic confession, don’t you think?"

Ayanokōji: "I really have no idea what you’re talking about."

Arisu says she wants to share the shock she felt at that moment when seeing his run. While still gripping her crane, she stands next to him and tells him it's been a long time, approximately 8 years and 243 days. Kiyotaka says he doesn't know her and starts walking in the opposite direction. Arisu smiles and says that it is natural for him not to know her, but she remembers him. Arisu then mentions the White Room.

Arisu : "It’s been quite a long time, Ayanokōji-Kun. Eight years and 243 days, actually"

Ayanokōji : "You’re joking, right? I don’t even know who you are."

Arisu : "Heh. No, I suppose not. It’s just me who knows you, after all."

Kiyotaka eventually stops walking. Arisu tells him that she knows that it is unpleasant when your opponent knows your secret. Arisu says that this was a reunion, and she just wanted to greet him. Kiyotaka looks back at Arisu without turning his back, believing that he only just met her at this school, perplexed by her self-proclaimed statement.

Arisu : "It’s unpleasant, isn’t it? When only your opponent knows your secrets."

Ayanokōji : "You…"

Arisu states that while he doesn't know her, she knows him. She said that she and Kiyotaka have a sort of strange bond, and she never thought that they might see each other so soon. She notes that she is aware that he was the one pulling the strings behind Class D's previous exam result. Kiyotaka attempted to stay composed and denies his involvement, stating that there were a few strategists in his class that were capable of that feat. Seeing how he doesn’t want to give in, Arisu eventually gives in and says that it does not matter anymore now that his existence has come to light.

Arisu : "Oh, it’s quite all right that you don’t know me. But I know you. We have a strange sort of bond, you could say. To reunite with you in a place like this… To be honest, I never thought I’d see you again. But now, all the mysteries have been cleared away. The island, the cruise ship, and Class D’s expulsion uproar. I couldn’t imagine that everything was on account of Horikita Suzune. So, you were the one pulling the strings."

Ayanokōji : "What are you talking about? There are lots of smart people in my class"

Arisu then states she has no intention of exposing him, claiming she's the only one worthy of burying the false genius and that she has found some ample enjoyment now that he is now in her life, thanking him for enlivening her would have been boring school life.

The two then made direct eye contact with one another. Kiyotaka then earnestly asks her if she could really bury him.

Ayanokōji : "Can you bury me?"

Arisu : "Hee Hee!"

Arisu laughs at his statement and added by saying that she's already begun to enjoy their interactions and announced that she will fulfill her life's desire by destroying the greatest masterpiece his father has made. Kiyotaka also wishes for her statement to come to fruition as well because his defeat would mean his father's defeat too, and he wants the sad contradiction he carries and is burdened with to be utterly destroyed.



In her short story, Arisu was reminiscing about the sports festival, more specifically dreaming of Kiyotaka Ayanokōji, and his race against Manabu Horikita, the student council president himself. She revealed that from her point of view, Kiyotaka was way faster than Manabu during that race (the only reason Kiyotaka lost the race was that one of the other participants incidentally tripped and fell to Kiyotaka's lane, causing Kiyotaka to lose the race by changing his track). After her monologue, she awakens and says that she 'wants him' while also wondering why he came to the school in the first place and questioned his reasons for being in D-Class. It didn't bother her if she ends up being his enemy one day. She began to enter into a long discussion with Katsuragi, about their competition with B-Class. She then mentioned how she initially thought Ryūen was going to be the main person to make things interesting for her — but that was until she was reunited with Kiyotaka. Arisu then asks Masumi to watch Kiyotaka closely and reflects on how much he has grown since the last time she saw him and that she will enjoy seeing what happens next.

Volume 6
During the Paper Shuffle special exam, Class A decided to target and attack Class B. This decision was Sakayanagi's and not Katsuragi's since Katsuragi would have chosen the much easier option which was (attacking Class-D). This showed the main decision-maker within Class A with Sakayanagi Faction holding the upper hand.

Class A won in their confrontation against Class B and was awarded 100 class points.

Volume 7
Later in the series, Arisu became acquainted with Honami Ichinose. As they walked together, they briefly met Ayanokōji Group and talked about how D-Class is fairing well with the recent test, The Paper Shuffle, which massively damaged C-Class' standing. Arisu stated that during the same test, both classes A and B sustained scores whose difference is reasonably insignificant, thus, concluding that both must have the same average intellectual abilities. Ichinose, teasingly stated that if her class doesn't have their guards up, surely, D-Class will surely take their throne. Teruhiko Yukimura made a snarky remark that not only Ichinose's class will be targeted, but also, eventually Arisu's as well. After he summoned his bold statement, an awkward situation started among all those present driving Arisu to laugh lightly to help ease the situation. Ichinose observed the Ayanokōji Group members' body language — that they might be feeling too uncomfortable with the two leaders being present, so they bid goodbye to the group.

Afterward, Arisu is seen interfering with Ryūen's interrogation of Rokusuke Kōenji. Following a long argument between the two leaders, the dialogue ended with them discussing the identity of "X". Just before Rokusuke is about to voice his thoughts, Arisu immediately stated that there is a possibility that "X" doesn't exist and that Suzune Horikita should be at the watch-list given that she's the one who manipulated the settings during the special summer exam at the deserted island.

The scene proceeded with Arisu being saved by Masayoshi Hashimoto after Ryūen violently assailed her for repeating Rokusuke's embarrassing nickname for him (e.g. "Dragon Boy"). After this, Rokusuke made a degrading nickname for Arisu (e.g. "Little Girl") which provoked her into proving that his naming sense doesn't give justice to the name-holder. The scene ended with Rokusuke stating that his thinking is beyond the realm of normal common sense and that no one is allowed to interpose with whatever he wants to say if not face his wrath.

In the short story, Sakayanagi calls Kakeru Ryūen telling him that she wants to meet with him in person at the vending machine outside the dormitory. When arriving later, 10 minutes late, Ryūen notices that Arisu's faction, Kitō, Hashimoto and Kamuro, are also there waiting for him, being Arisu's bodyguards. Arisu mentions Ryūen's visible injuries, having suffered from his defeat at the hands of Kiyotaka Ayanokōji on the rooftop, which sparks some provocations between both sides. Arisu then says that she wants to ask Ryūen about his fall from being C-Class' leader. Arisu wants to know wheather it was because of Kiyotaka, Kakeru notices this. Ryūen asks if Arisu would ever acknowledge a defeat, being a prideful person. Arisu replies that she cannot possibly lose to someone, and a life without pride would be boring, to which Ryūen argues it is pointless to have a life of showing off one's pride. Arisu then tells the reason she wants to meet him directly like this, stating that it is hard to believe Ryūen, being a tyrant, would lose to his subordinate and fell from his leader position. Ryūen declares he has no further intention of doing anything else in the school, causing a reaction from Hashimoto. Arisu talks about his contract with Katsuragi being a pathway for Ryūen, while also warns that there is no guarantee it will continue to go well for him, in case he loses a large amounts of points. She then reassures that her focus of attack is now on B-Class, to which Ryūen has no objection. Ryūen decides to leave, his last words to Arisu being a reminder that she is not a winner whose victory is guaranteed, which she acknowledges. Ryūen reaffirms he has no intention of being involved in classes dispute, but believes he will crush Arisu if she were to individually challenge him.

Volume 7.5
During the winter holidays, Arisu runs into Kiyotaka and they decide to converse. She reveals to him that she has already heard about Ryūen stepping down as leader, considering only 1 day has passed since the incident at the rooftop, Arisu's network of information seems to be extremely efficient. Arisu asks Kiyotaka if he was the one who defeated Ryūen to which he denies that he had any involvement in that situation. Nonetheless, she doesn't press any further. Instead, she says that she felt left out due to class D and C having their own battles and that she wanted to find an opponent for her own to play with, having decided on Ichinose. Arisu tells him that she plans to attack her at the start of the next term and that if she were to disappear, she might have no choice but to find other targets to destroy. At this point, Kiyotaka tries to get her to focus her attention on Ichinose by revealing that he wonders if she is good enough to destroy her since she perhaps got into class A because her father was the director of the school. Arisu doesn't appreciate his provocation. As they were talking, Kamuro comes looking for Arisu telling her not to disappear from their arranged meeting place like that. With Kamuro here they started talking about whether Ichinose really is a good person, and she reveals a little about Ichinose's secret to Kiyotaka and Kamuro saying that the secret Ichinose keeps is the same as the one Arisu uses to control Kamuro. Kiyotaka asks why Ichinose would tell her something like that to which she said Ichinose told her about it herself. She also said she obtained the information via cold reading. With her warning given, Arisu and Kamuro go off to hang out together.

Volume 8
Arisu is participating in the Mixed Training Camp while nothing much happens among the first years, an incident where Haruki Yamauchi bumps into her causing her to fall down setting up the stage for her future plans and igniting a personal vendetta within herself. Yamauchi who was not the most sensitive person offends Arisu with his insensitive attitude and remarks. Kiyotaka who watched the scene unfold noticed the situation and her change in demeanor, thus, apologizing on his behalf by telling her Yamauchi didn't mean it, Arisu says she understands that but her face showed a much darker emotion. Before they parted ways, Arisu once again asks for Kiyotaka's thoughts of whether he thinks class B can wholeheartedly trust Ichinose as their bank to which Kiyotaka replies that that should be up to Ichinose's class to decide and not their business to speculate. {{SpoilerSection|id=LNPlot|

Volume 9
After the mixed training camp as the winter term begins, Arisu begins her attack on Ichinose and her class. She starts by spreading rumors about her through the class A students before spreading them towards the entire school. The rumors being spread are: 'A History of Violence, 'Engaged in Compensated dating', 'Engaged in theft and robbery' and 'A history of drug abuse. While Ichinose deals with these rumors by simply ignoring them, which Arisu expected to happen. Arisu's plan was for some students to questions if there were potential truths being spread among the rumors, and that if Ichinose were to complain to the school, her past would have to be revealed as a result, shattering her perfect girl image. After a few days, it appears as though there was no truth to the rumors as Ichinose successfully ignores them. However, Arisu continues her attack by using post boxes of the students with a letter revealing that Ichinose is indeed a 'criminal' in the past. This attack seems to have a successful mental effect on Ichinose who becomes a shut-in after seeing the letters. On the day she sent the letter, she also sent Kamuro to go and tell Kiyotaka about what Ichinose's secret is. With Ichinose's absence, more students began to speculate that the rumors may be legitimate.

To make good use of her time, she went to launch another attack she had already pre-planned. One day, Arisu visited the class C classroom looking for Yamauchi, under the motive of 'hoping to talk to him'. They went to go talk outside the classroom where to onlookers, she appears to be fiddling her hair like a girl trying to appeal to the guy she 'likes'. As there are actually multiple students watching them, she teasingly asks if they could go somewhere more private, playing him into her hands.

On the day that Ichinose finally returns to school, Arisu takes her faction with her to visit the class B classroom to continue her attack, revealing Ichinose's past to Class B herself saying that she was a thief and that her class should not trust her with their money. In response, Ichinose decides to reveal the whole truth to everyone present and offers to step down as leader of class B as recompense for not telling them beforehand. However, astonishingly her classmates unanimously had a consensus and did not want her to do that as they believe in her. In response, she says she will continue working for the good of the class. Listening to the entire ordeal play out, Sakayanagi seemingly unsatisfied told class B that a crime is a crime and that they shouldn't be so quick to trust her again no matter the reasoning, especially in their society. Seeing that her assault was not working, she praised the unity of Class B and proceeds to say that she will continue her attacks soon. The school staff soon arrives and says that slander and rumors will no more be tolerated by the school as more students have been affected and started complaining, due to the rumors that Kiyotaka himself chose to spread. Upon hearing his name, she was amused and decides to take her leave.

When that was over, she calls Kiyotaka and requests to speak with him. The first and only question she asks him was his rationality in helping Ichinose, as the rest of the questions had already been figured out correctly by her. Kiyotaka returns the question by saying that he was just playing his part as that's what she actually wanted by sending Kamuro. Telling her that he knew it was her plan for him to help Ichinose as a way to challenge him in the background. Although Arisu denies this at first, she continues by asking why he thinks that. He tells her that the beer can Kamuro had passed to him had an expiry date far too old to have just recently been stolen which meant that it was the beer can that Arisu had caught Kamuro stealing at the start of their school year. In order words, it was her plan to have Kamuro reveal that secret to him, although in a very indirect manner. Arisu is impressed that he saw through all of it and says that he is indeed an enemy worth defeating as expected of him. She directly challenges him to face her next time, lightly threatening to expose his secret if he chooses not to do so. Although Kiyotaka thinks she won't resort to doing that either, even if he had rejected her offer. In spite of that, Kiyotaka eventually agrees to face her in the next special exam with her expulsion on the line as a means to remove her so she won't be able to reveal his past and disrupt his peaceful school life.

Volume 10
On the first day of the supplementary Class Poll special exam, Arisu, and Kamuro happened to meet Kiyotaka. They discuss the current exam saying that it seems very unreasonable, with Arisu revealing that her father the director has been removed from his post by dirty tactics which may explain why the exam is so different from previous exams. Arisu asks Kamuro if she wonders why she was so interested in Kiyotaka, Kamuro replies saying she indeed was. Arisu replies by saying that they knew each other from way before they came to this school. Kamuro wonders if Kiyotaka was even a worthy opponent for her as she can't see that at all when even the other class leaders are insignificant to her. She surprised Kamuro by saying that he was different from the others and is not one to be underestimated. She then tells Kamuro to leave so that she can privately talk to Kiyotaka to discuss their deal. She tells him that this exam isn't suited for their battle, so she wants to postpone it to the next exam. Seeing no reason to disagree, Kiyotaka agrees with her idea. She even reassured him that she will take no actions that will harm him in this exam at all. Thereupon, Kiyotaka wonders who she will expel from her class, and she tells him it's already been decided to be Katsuragi.

She continues to put her plans into motion. Before they happened to meet Kiyotaka, Arisu had made plans to meet with Yamauchi that night. Kamuro was curious as she noticed that Arisu had seen her contact with more often recently. She asks if Arisu 'likes' him, but she reveals she has just been training a spy within class C and this exam is the perfect exam to test who he truly is and show everyone his true ugly nature. They soon decided to meet in the karaoke room. Arisu brings Kamuro along for the 'date' saying that she is too embarrassed to go on a date with just the 2 of them. She tells him that she wouldn't want to see Yamauchi expelled so if he needs help he should ask her, successfully gaining his trust by playing to her words. Arisu tells him that he should target another student to save himself. Kamuro understanding the logic behind her plan offers Kiyotaka as a sacrifice. Yamauchi is afraid as targeting someone else will make him the target as well. Arisu soothes his anxiety by offering 20 of her class praise votes as protection to him so that he won't be expelled. When Yamauchi leaves, Arisu and Kamuro discuss how strong Kiyotaka really is, Arisu says no other class leader like Katsuragi, Ichinose, or Ryūen has an ink of a chance against her but as for him, she wasn’t so sure. However, a part of her wants to be able to lose to him. Wondering how strong he really is, and hoping to see his full potential she plans to put him in a bind where he is going to be expelled by her hands to test her capabilities.

After a day goes by in the class poll exam, Yamauchi successfully amassed about half his class to vote for Kiyotaka due to Kushida's help and her disdain for Kiyotaka. On Friday the day before the exam, Yamauchi tells Arisu that he has been exposed as the ring leader and the target. He calls Arisu wanting to confirm that he will receive her class praise votes. She promises that he will. Previously, Hashimoto had previously advised her to not include Kei Karuizawa in the students targeting Kiyotaka but for some reason, she did it anyway. However, she made it so through staggered timing, making sure to only include her on Thursday to ensure whether Kei was really helping Kiyotaka in the background, since Kiyotaka made his move on Friday, it eventually confirmed her suspicions. Hashimoto asks why she included her despite considering it in her plans. She informs them that she had forgotten to tell them something very important up to this point and proceeds to tell them. While it is not revealed what she says, it is inferred she told her that their praise votes will be going to Kiyotaka instead and that Yahiko Totsuka will be expelled instead of Katsuragi. The outcome of the class poll exam was Kiyotaka receiving many of Class A's students' protection points thanks to Arisu's intervention and Yahiko being expelled.

After the exam, she meets with Kiyotaka telling him that this exam was most likely made to expel him as she had received a message from someone asking her to expel him. That most likely the exam would have students from other classes being able to cast criticism votes on other class students making it easy to expel someone they didn't like in another class. After receiving this information Arisu had decided to protect Kiyotaka from the very beginning. As they were talking about the outcome of the exam, Acting Director Tsukishiro comes up to them asking for directions and introduced himself, saying he will officially start in April. As he is about to leave, he attacks Arisu by kicking her cane away almost causing her to fall down but Kiyotaka successfully grabbed ahold of her and puts her down softly on the floor. Tsukishiro then grabs Kiyotaka ordering him to resign from the school himself. He doesn't retaliate causing Tsukishiro to leave. Arisu said it was a good idea not to fight back as although he told them that the cameras were not recording, it could have been a lie. Kiyotaka then remembers their past deal and challenges Arisu to a duel in the next exam as with Tsukishiro here their battle might be interfered with so he wanted to get it done as soon as possible.

Volume 11
Sakayanagi gives a monologue where she reminisces about her trip to the White Room with her father. Among the many children in the White Room, Kiyotaka Ayanokōji seemed to be the only one capable of calmly beating one opponent after the other in chess and was the only one to attract Sakayanagi's attention. Sakayanagi's father didn't want the experiment to succeed because its success will likely force many other children to suffer the same unfortunate fate as Ayanokōji, and the children will similarly not receive their parent's affection. Sakayanagi promised her father that she would defeat anyone from the White Room because she has the superior DNA she inherited from her extremely talented mother.

Right before the start of the exam, Arisu found herself alone in the multi-purpose room with Ayanokōji. Her heart was palpitating just from being in the same room as him. Every time she tries to steal a glance at him, her body couldn't stop itself from being attracted and has great difficulties turning herself away.

Arisu : "Fufu, just like a maiden in love, isn’t it?"

She knows she was a maiden in love and thoroughly enjoyed the newfound emotion from the bottom of her heart. It was revealed she couldn't sleep the night before and almost overslept due to the excitement of spending time with him. She stammered a bit since it was the first time having difficulty raising her voice for a while. Ayanokōji looked a bit troubled but replied, telling her that he meeting her was nothing but a coincidence in the first place. Arisu tells him that his meeting with her at this school might have been a coincidence, however, she was convinced that she would again meet him someday. It was meant to be fate.

Kiyotaka : "Fate? That's quite an abstract thing to say."

Arisu : "If this wasn't fate, what else would you say it was?"

Even if Kiyotaka didn't enroll, Arisu was confident that she would meet him one day. It was also she was also a maiden in love with him. She had confidence that she could hide her anticipation deep inside her heart without rushing it. But she couldn't hold it back anymore. Inevitably she felt the days becoming longer and longer knowing Kiyotaka was by her side. Her fight for suppressing that feeling has been quite tricky and hard to suppressed. She truly loves Kiyotaka Ayanokōji. She was thinking of him as her childhood friend, although selfishly and was hoping for him and her to be closer. That's why Arisu couldn't stop the overflowing words by her own will. She was talking to Ayanokōji non-stop as if yearning for him, one topic after another. That calm look Ayanokōji gave Arisu and the sight of his pupils give her more pleasure.

Arisu asks herself whether she is afraid from waking up from this dream of herself with Ayanokōji-Kun. She knows that when one wakes up from dream and returns to reality, happiness will disappear for a moment. Fighting Ayanokōji and losing will result in despair. Whereas winning so easily that nothing is left other than disappointment. She couldn't overlook a chance that this could happen. But that was fine.

Arisu : "Because dreams are things you are meant to wake up from. "

She asks Ayanokōji to fight with her with all he has got. Ayanokōji responds with a nod. At the same time, Arisu could begin to guess what he had in mind. The thing that was keeping Arisu from enjoying herself to her fullest- Kiyotaka's true identity. They then discuss about the exam and how limited the leaders intervention is throughout the exam. But if the leader's influence was too large another problem would have arised- Kiyotaka's classmates identifying his true abilities.

The special exam was a secret duel between Arisu and Ayanokōji. It was just an extension of a game, played in secret unknown to the teachers and other students. That's why it was understandable for Ayanokōji's suspicious behaviour. Next the teachers were approaching. The special exam was going to start soon. After sitting in the respective seats alloted to them for the exam, Arisu could no longer see Ayanokōji's face. But she doesn't want to be discouraged by that, because as long as both of them are in the same room, she could talk to him anytime and ans many times she wants.

Arisu : "Best regards, Ayanokōji-kun"

Arisu sent a greeting to his direction in a voice so low that nobody could hear. She supresses the countinuous throbbing of her heart and now it was time her dreams will be realised.

During the Event Selection Exam, she was the commander for Class A. Class A eventually won the exam thanks to her leadership and strategists and with her winning the last event - Chess, with Sakayanagi defeating Ayanokōji. It also attracted much attention to Kiyotaka as he was capable of going toe to toe with her. It is later found out that Tsukishiro had somehow intervened with the school systems and changed Ayanokōji's move to an inferior one, which Sakayanagi was able to beat. Sakayanagi was disappointed upon finding out as remarked that adults shouldn’t disturb children from having their fun. She politely asked Ayanokōji for another match in the library and to show her his actual winning move after the competition. When Ayanokōji played his actual move, Sakayanagi found herself in check-mate. Both of them complimented the skills of the other with Kiyotaka remarking that in a few more games, she would win pretty handily against him due to her constant improvement.

Volume 11.5
Arisu gives Chairman Sakayanagi's number to Kiyotaka. She said that she knew Kiyotaka might run into trouble one day and might need his number and assistance. But, when Kiyotaka calls the Chairman, he says that he never gave his number to Arisu, meaning that Arisu got it from somewhere else, displaying her resourcefulness and cheekiness.

Later on, during Ayanokōji's meeting with Chabashira and Mashima, Sakayanagi appeared to have followed Mashima sensei to the reception room. She told Mashima that she was also related to the incident; hence Mashima brought her along with him. To Ayanokōji, it seemed that she was just curious to know what was going on.

Kiyotaka invites the two teachers to take a seat, but since Arisu is crippled, Mashima offers his seat. As soon as Kiyotaka mentions that the meeting is taking place because of matters related to the acting director, both teachers are shocked and became apprehensive. On the other hand, Sakayanagi shows an innocent smile to ease the tension and expressed her superior knowledge of the entire situation.

Arisu helps Kiyotaka explain the situation to the teachers. She says that she and Kiyotaka are childhood friends. The teachers were surprised to hear this considering their difference in status. After that, she tells them that the original winner of the chess event in the Event Selection Exam was in fact Ayanokōji-Kun, and someone from outside had stepped in to interfere and change Ayanokōji's move manually to an easier one who made her win. Chabashira got surprised upon hearing this. Arisu explains that all the chess steps were passed and processed by the school system first before sending it to participants. Arisu says that Kiyotaka's father suspended her father Chairman Sakayanagi and sent Tsukishiro to expel Kiyotaka from school to attempt to expel him.

When Mashima-sensei asked who Ayanokōji truly was, Arisu tells them that he is an extraordinary person better than any other boys out there, saying that she knew about Ayanokōji better than any of them.

She then states that she intends to stay by Ayanokōji's side for the time being. Mashima argues that if she is seen giving special treatment to Ayanokōji, many questions might be asked. Sakayanagi rebutted Mashima's words asking him what's wrong and if there was a problem with providing Kiyotaka special treatment. She says that although the school system revolves around a competition between classes, some may have friends or lovers from other classes who prioritize each other over their classes. Sometimes, one's feelings can go beyond the boundaries of classes, forming mutually beneficial relationships with people from other classes. Even if she could only save Ayanokōji-kun and leave her classmates in Class A, the teachers can't blame her if she decides to do so. The only ones who can blame her are the students she has betrayed. However, she says that this favoritism exists for Kiyotaka only. After Acting Director is gone, she will not hesitate to crush his class. Mashima considers that as an acceptable compromise.

Later, when Ayanokōji leaves with Sakayanagi, he finds her smiling. She says that she is smiling because this situation that presented itself seemed fun. Ayanokōji thanks Sakayanagi for coming and increasing his chances of persuading Mashima-sensei. Sakayanagi requests Ayanokōji to let him rely on her to get rid of Tsukishiro, becoming something akin to a lifeline or secret protector for him.

2nd Year Volume 1
During the Partner Special Exam Ichinose invited students from both the first and second years to meet up and interact to improve their relationships. Sakayanagi did not come to this event. She understood that all the students gathered would be those seeking partners not to win but to avoid expulsion. It was eventually found out that Sakayanagi and Ryūen were spending private points to attract the students to their side.

Arisu was first seen in a cafe in Keyaki Mall along with Masumi Kamuro and Hayato Kitō. They were discussing how the Partner Exam was going to be conducted by the school. Kamuro was on the phone with Masayoshi Hashimoto, relaying his findings to Sakayanagi from across the table. Masumi reports that Kakeru has offered 100,000 points to a first-year that they have set their sights on and that he will increase the offer up to 200,000 if the number of pairs scores above 501 marks. Class C was also straight-up, offering 10,000 points to the first-years who declines Class A's offer. Kamuro asks to fight Ryūen's proposal with their private points. However, Arisu turns down her proposal for financial battles. When Kamuro asks whether she plans to lose, she says there is a significant difference in academic power between Ryūen's Class and her Class A. If he wishes to overcome this special exam, he has no other choice but to spend private points. She comments that Ryūen might have changed strategies: instead of buying his way to the top Class using a million points like last year, he has now decided to rise by increasing his class points.

She says that Ryūen's strategy was not necessarily a bad one. He has forced Arisu to play along with this money game of his. However, he only targets the same students Class A is going for, which is a miscalculation made by him. As Class C is the more inferior Class, Ryūen should have focused on the more academically gifted students.

Arisu then decides to counter with a strategy to pay the same amount of points but not partner up with students or give them the points. This way, Kakeru will be forced to offer more points and lose the money game while class A is not involved at all. Kamuro does not understand the logic, so Arisu explains by saying that Kakeru is trying to force class A into a financial game, targeting the same pupils as class A. However, by using her strategy of pretend-money, Kakeru will have to offer up more money. For them, however, they will be able to reel in students with their Class A reputation. Kakeru simply thinks that their good reputation is nothing more than a label, a status that can go away if people view Class A in a negative light. Nevertheless, she sees a miscalculation that can be exploited on his part. Kamuro still does not fully understand Arisu's strategy, she feels that they are being forced to go along with Ryūen's strategy, but Arisu tells her to follow the instructions and rest assured. She hopes that Ryūen doesn't self-destruct after this since then it won't be of much fun afterward. Arisu hopes that her upcoming opponent was somebody worth facing off against and that she won’t be disillusioned.

2nd Year Volume 2
Feeling the need to make a small group quickly for the Uninhabited Island Exam, Sakayanagi contacted Honami Ichinose on a particular day to discuss about group formation. It was Friday of the first weekend after group formations had started. Sakayanagi gave a sudden invitation to Honami Ichinose on short notice to have a face-to-face meeting privately with the latter at a cafe concerning the uninhabited island exam that was set to take place in the summer without giving her much time to think over. If Arisu didn't carry out this strategy earlier than anticipated and had she been told a few days in advance, Honami would have speculated on what the meeting would be about. Sakayanagi's quick invitation was a strategy so that Honami won't have much time to think and be forced to agree to her terms. Depending on the occasion, she might have even ended up going out of her way to ask a classmate like Ryūji Kanzaki for help with Arisu's invitation. However, since it was already Friday of the first weekend when the group formations had started, Honami decided to accept Arisu's invitation anyway and arrived at the designated site, where the latter was already waiting for her. Upon arrival, Arisu questioned Honami about why she agreed to meet up with her. Honami replied saying that she didn't have anything else on her schedule. Sakayanagi pushed the matter further, telling her that she has done terrible things to her, and she wouldn't be surprised if Honami hated her. Realizing that was not what Arisu meant by her previous question, Honami conveys her feelings about how she isn't bothered by the terrible things Arisu had done to her as she wants to let bygones be bygones. In fact, Honami explained how she did not harbor any hatred or resentment towards the former for exposing her past or betraying her trust but actually genuinely thanks her for teaching her a valuable lesson and for exposing her naivety. Honami said she didn't think whatever Arisu had done was anything excessive, telling the latter that it had helped her reflect on what happened during middle school and come to terms with her shameful act. Hearing this, Arisu described Honami as a good person, to which Honami got a little embarrassed. Honami started scratching her cheeks lightly and averting her gaze as if she couldn't handle the sight of Arisu gently gazing at her.

Arisu understands that Honami wants to quickly move on to the main topic of the discussion. Hence, she decides to just do that and respect her wish. She tells Honami that it might not be a very comfortable topic of discussion for her, which caused Honami to silently pray for Arisu to go easy on her. Sakayanagi said that as a warning. Although Honami was not comfortable with the direction the talk seemed to be heading towards, Arisu started with it anyway, explaining Class-A's predicament before the Uninhabited Island Exam, saying that Class 2-A was naturally feeling the danger as Kakeru Ryūen 's Class 2-B is approaching them once again. After Arisu stated her concern regarding Class 2-A, Honami, who was the leader of Class 2-C, was then asked by the former about her thoughts on that potential problem looming on the horizon. In more ways than one, Arisu had mercilessly pointed the other dilemma besides Class 2-A, where Honami and her Class 2-C were also being left out in the cold from both Class 2-B led by Kakeru and Suzune's Class 2-D. Sakayanagi mercilessly pointed out this situation where Ichinose and her class were being left out and not being treated as a threat. She showed a deliberate smile towards Ichinose as she could not answer momentarily and started fanning herself with a bitter smile. Sakayanagi started feeling that the conversation is going according to the exact way she has planned it to. After being given some time to process what Arisu had said, Arisu makes Honami admit and acknowledges the fact that it was true that Class 2-C was feeling excluded and ostracised from the two classes, which was not a good sign as that was the result of her failures to lead. Sakayanagi was in no mood to respond with sweet words, her plan to instill fear into Ichinose for falling behind and getting left out worked perfectly. She also made Ichinose feel the thick and potentially dangerous students that are hidden in Class D. She said that there are many talents laying domain in Class D including Hirata and Kushida who have strong communication skills as well as having well-balanced grades, along with Sudo-Kun, who is the only one to get an A+ rating in physical ability in the entire 2nd year. They also have hidden cards like Kouenji and Ayanokōji, whose extent of abilities are still unknown. She concluded by saying that Class D is now being led by Horikita-san, who has excellent academic and physical abilities and has recently joined the student council. She forcefully makes Ichinose reaffirm her current situation of being left out in the cold and feeling unsettled that she isn’t progressing at the same rate as them. She told Honami that her class will inevitably fall to Class D sooner or later at this rate. Honami tried to deny it, but Sakayanagi simply took the words from her mouth and made her swallow back what she was about to say. She then decided to praise her after shattering her by saying that Honami's class has something that no other classes can beat and something extremely potent which was unconditional trust between classmates. She acknowledges and recognizes Honami for being able to establish such a feeling and said that it would be extremely important in a partnership between classes.

Remaining speechless and silent by that statement, Honami was attacked further by Arisu, who asserted that it was almost nigh impractical to win with simply believing in these kinds of vague things no matter how hard the former tried to make such abstract values work successfully as they would always fail in the end. Honami continued to get belittled and denigrated by Arisu, who explained that three of the four classes (A, B, and D) had clearly been improving and increasing their strength over the year, while the same could not be said for Class 2-C as the latter did not see much growth happening in it. Arisu didn't argue against the notion of them growing up but stated it was a matter of the amount of growth in how much they have grown, implying their improvements were too little and minuscule to compare with Classes 2-A, 2-B, or 2-D. Honami says that her class won't lose to any of the other classes. Arisu, not believing a word she says, counters her statement saying that if Honami had looked at the OAA app and analyzed very carefully, it was evident at first glance that Class 2-C was the one who had grown the least among the four classes after comparing the overall abilities of when they were 1st years to 2nd years. Arisu, surprised, thought Honami would've already done that level of analysis as her and reached the same conclusion like she did, which caused the former to cast doubts on whether the latter even knew the facts all along and pretended not to notice or did not even dare check them for fear of facing the cruel reality of Class 2-C's situation. Being driven into a corner by Arisu, who came off as harshly critical of her and her class, Honami recalled when she was alone with her and how the two of them were like a child and an adult arguing back and forth, respectively.

Arisu repeatedly attacks Honami's weakness. However, she also acknowledges her ability and potential to be an intelligent student.

Arisu states that she failed to use her true strengths to the fullest effect whenever Honami was in an unfavourable situation outside her strategic control. Arisu confidently declares that she stood no chance in winning against any of the three classes due to how less Class 2-C's growth had been the last year. Hearing enough of the argument, Honami asked Arisu if this discussion was what the meeting was all mainly about finding fault with her and why she had been invited to the café. Arisu replied that it was not the real reason Honami had been given an invitation in the first place, explaining how she could've persisted with this kind of conversation anywhere else that is not related to the meeting and not waste her precious holiday time on it. Finally deciding to get to the main point of the discussion, Arisu then asked Honami to cooperate with her between their two sides, Class 2-A and Class 2-C, much to the former's disbelief and astonishment at the unexpected proposition.

Bewildered by the sudden proposal, Honami was asked again by Arisu to consider the latter's offer as this was the only way for the former to catch up to Class 2-A. Arisu tries to reason with her that a cooperative relationship between their two classes was not entirely a bad idea for either side to have, taking the example of Honami's cooperative relationship with Suzune of Class 1-D when they were 1st years. She quickly explains this before Honami can give her say in the matter. Arisu was able to ultimately deduce how her class alliance with Suzune had ended due to recent achievements of Class 2-D having given that group a lot of incredible momentum going on for them to catch up when it came to accumulating more class points than any class while being the most successful of the four classes last year despite starting from nothing but zero. Arisu wanted Honami to realize that this had happened solely because of her own negligence with her classmates, where they took a step back and fell down from Class 2-B to Class 2-C was what allowed Suzune to think there are no longer any advantages in continuing to work with them. By pointing everything out at her, Arisu made Honami admit that partnerships didn't always last forever. Arisu wanted a partnership with Honami because of the massive difference in points between Class A, and Class C. Arisu reasoned that this partnership is of value when the powerful weapon Honami possesses known as "trust" was what she greatly wants in an alliance and could care less about the shortcomings of her fighting strength. In other words, Arisu emphasized to Honami that it's a very important factor to consider as worthwhile when seeking to create an alliance based around trust, thinking she can be entrusted to watch her back. Honami, however, informs her that Class 2-C is currently in a bad situation where they don't care much about the weapon being "trust" anymore. On the other hand, Arisu cast her doubts if Honami and her class will really go as far as to relinquish their "trust" and throw it away after spending one year of building up such a weapon and developing it. Arisu informed Honami that if Class 2-C's betrayal occurs, it will be the latter's own fault for having misjudged the former.

She was surprised when Honami took a shot back at her by threatening and floating the idea of allying with the other classes to take down Class A, which Honami states that she knows that was something Arisu was trying to prevent by approaching her in the first place. Seeing how Honami was able to see through her actions, Arisu praised her genuinely and admitted that she truly underestimated her. This causes Honami to blush. Additionally, she gave in to Honami's demands of securing private points for them so Class C will be able to protect those on the precipice of expulsion and eventually was able to secure their class alliance with a handshake.

}}

Abilities
Along with Kōhei Katsuragi, Arisu leads Class 2-A and has a loyal group of followers that would faithfully do everything she orders. Despite her limited physical ability due to birth defects, Arisu is notable for her talents as being the only person Katsuragi reports to, despite his own outstanding academic prowess and leadership skills. Manabu Horikita the former student council president even praised her phenomenal holistic management of her class, such as being able to stand out from the rest of the classes in terms of class points despite only having a handful of weeks to establish her control, and personally invited her for a chat to commend her achievements.

She is also shown to be resourceful as when she was unable to go on the school cruise, she had Masumi Kamuro conduct research on certain students and Masayoshi Hashimoto to physically manifest her plans in her stead.

Academic Abilities
Arisu is known for receiving great scores throughout her school-year and has the highest overall score for her year in the OAA. Even Manabu Horikita, the previous Student Council president at that time who has extremely high standards, praised her grades in the recent midterms. This was notable, as the only other person he had ever been seen complimenting was Kiyotaka Ayanokōji, who is extremely intelligent and skilled in manipulating his academic ability in his own right. She easily boast one of the highest academic and adaptability grades in the entire school's history. During the Partner Exam, where many questions had difficulty equal to college questions, she was acknowledged by Kiyotaka Ayanokōji for achieving high grades in them, though she didn't go to any sort of facility like White Room

Intellectual Abilities
Arisu is known for her vast intelligence, which even garnered praises from many people from other classes such as Honami Ichinose, the representative of Class 1-B who reported to her teacher Chie Hoshinomiya that Arisu is someone they had to actively watch out for. She is also very manipulative, cunning and perspicacious in her plans which can only be rivalled by Kiyotaka. She knows how to play to her charm and beauty and isn’t above using them to get to her objectives such as expelling Haruki Yamauchi.

One of the way she does this is by playing to the strength of her allies while targeting the weaknesses of her enemies, crippling them before them can attack. For instance, she was able to emotionally scar Honami Ichinose the leader of Class 1-B by revealing her secret, effectively taking out the leader of the second best class and their chances of competing with her.

Additionally, she played Honami to her advantage by exploiting Honami's kind and forgiving nature by forming an alliance with them before other classes could. She is also very good in chess, perfectly capable to be on the national level and even cause difficulty for Kiyotaka who was trained from young to be virtually perfect in it. She is easily able to factor in her opponent's idiosyncratic thought processes in her plans, thinking more than 10 steps ahead of them and countering them in the span of seconds.

Her deduction and analytical skills are one of the highest in the entire school and on par with Kiyotaka when he is serious. She is easily able to lead and have dominion over most of her classmates in Class 2-A who are full of distinguished students and individualistic personalities and have them obey her every command. Kamuro was surprised to hear her saying that she wasn’t sure if she could defeat Kiyotaka when she indirectly says that she is better than Ichinose, Ryūen and Suzune.

Name Etymology

 * The name Arisu consists of kanjis that mean "exist" (有) (ari) and "tree" (栖) (su).
 * Arisu's surname Sakayanagi consists of kanjis that mean "slope" (坂) (saka) and "willow" (柳) (yanagi).

Quotes

 * ( To Kiyotaka Ayanokōji): "It's been quite a long time, Ayanokōji-kun. It's been eight years and 243 days actually "
 * (To Kiyotaka Ayanokōji): "Oh, it's quite all right that you don't know me. But I know you. We have a strange sort of bond, you could say. To reunite with you in a place like this... To be honest, I never thought I'd see you again. But now, all the mysteries have been cleared away. The island, the cruise ship, and Class D's expulsion uproar. I couldn't imagine that everything was on account of Horikita Suzune. So you were pulling the strings."
 * (To Kiyotaka Ayanokōji): "Sorry for laughing. I didn't intend to insult you. I know quite well how incredible you are. I've been looking forward to this. I'll be able to realize my dearest wish by destroying the greatest masterpiece that your father ever made."
 * (To Honami Ichinose): "Only by a slim margin. Two points. I think we were just about evenly matched."
 * (To Kakeru Ryūen): "I'm here purely by coincidence."
 * (To Kakeru Ryūen): "This is a fascinating conversation. Someone in Class D is getting in Class C’s way, are they? I heard rumors that Dragon Boy-san was searching for such a person, but is that really true?"
 * (To Kakeru Ryūen): "My, my, you don’t like it? I think it’s a wonderful nickname. Sorry. Anyway, there’s something here that I don’t quite understand."
 * (To Kakeru Ryūen): "Someone in Class D saw through your plans and defeated you. Is that all there is to it? This school is fundamentally designed to pit classes against each other. You and I have clashed numerous times in this manner. I don’t know who this Class D student is, but they’re employing excellent strategy by remaining anonymous while waging war on you. Are you really going to expend all this energy on interrogating an unrelated student? Honestly, I can’t see your actions as anything but rather pathetic."

List of Short Stories
These are a list of short stories involving Arisu Sakayanagi.

'*'Scene not included in Light Novel.(Extra plot)

Trivia

 * In the light novel, Arisu debuts in Volume 5; however, in the anime, she first appears in Episode 1, which chronologically takes place much sooner than the light novels.
 * Arisu ranks #21 in the "Female Character" category in the 2021 edition of 's  guidebook.
 * For the 2nd Year arc, when asked about her aspirations for the next year, she answered  'To lead a school life that's interesting... And protect my beloved person from unwanted vermin I suppose.'