Sakayanagi Arisu

Biodata

Feature	Value
Name	Sakayanagi Arisu (坂柳有栖)
Alias(es)	“Princess,” “Miss Arisu” 3 8 36
Gender	Female 2 6
Affiliation	Advanced Nurturing High School; Class 1-A; Seven Stars group 2 24 25
Occupation/Role	Student; member of Class A’s leadership; custodian of the class’s pooled private points 4 27 30
Family	Daughter of Chairman Sakayanagi, the school’s board chairman 3
Status	Enrolled; Yagami’s proposed treatment for her physical condition has not been shown to succeed in the supplied chapters 24 36 41
First Appearance	Chapter 2, observing Yagami Shizuka’s interaction with Katsuragi Kohei 2

Background

Arisu enters Advanced Nurturing High School as a Class A student. Her excellent grades and position as the chairman’s daughter help her secure a place in the class leadership. She has also studied the manners and etiquette of a noble young lady 4 8.

Through her father, she knows about the White Room and its methods of producing artificial geniuses. She rejects the idea that artificial geniuses are superior to natural ones, but recognizes that White Room students should not be underestimated 25.

Her physical condition has resisted numerous medications and consultations with doctors. When Yagami claims that he can help her obtain the healthy body of an ordinary person, she initially says she does not believe him, although she eventually agrees to provide financial support 24.

Original Fate and Yagami’s Intervention

In the original storyline known to Yagami, Class A divides into the Katsuragi and Sakayanagi factions. Arisu eventually withdraws voluntarily, with Yagami identifying her willingness to leave at Ayanokoji’s word as a central obstacle to saving her. These are anticipated outcomes, not events that have occurred in the supplied storyline 2.

Yagami’s system presents a first-day confession to Arisu as the route to a different ending. His decision to pursue her begins the attempt to rewrite both her fate and Class A’s future 2 3.

Appearance

Arisu is a petite, frail-looking girl with purple eyes. She wears a hat and uses a cane, contrasting her delicate appearance with a calculating manner 2 3 6 25.

• Small stature: She stands near the front in entrance-ceremony photographs because she is not tall 17.
• Cane-assisted movement: She walks slowly and becomes exhausted when trying to increase her pace 17.
• Limited stamina: Even ordinary walking leaves her winded; stairs are particularly difficult 36.
• Expressive reactions: Her composed smile gives way to puffed cheeks, blushing, and visible irritation during exchanges with Yagami 21 24 39.

Personality

Arisu is observant, proud, and strongly competitive. She quietly watches classmates before acting and enjoys humiliating talented opponents, particularly geniuses. Winning a particular contest matters less to her than retaining the initiative over the people involved 2 3 6 7.

Her desire for control extends to allies. Although Yagami publicly presents himself as her subordinate, she recognizes that he often uses her authority for his own purposes. Rather than accepting this arrangement on trust, she seeks weaknesses that would let her restrain him—even considering manufacturing leverage if observation reveals nothing 17.

She is willing to use deception and blackmail without insisting on a fair contest. Nevertheless, she considers proposals that benefit the class and approves Yagami’s disciplinary policies despite disliking his habit of acting without permission 11 19 36.

Her attachment to Yagami develops alongside jealousy and uncertainty. She discourages other girls from approaching him, but later accepts inexpensive meals, enjoys his reassurance, and openly thanks him for defending her. Her growing affection does not erase her frustration with his independence or her wish to surpass him 15 16 21 22 32 39.

Abilities & Skills

Factional Strategy

Arisu designs contests so that an apparent defeat can still strengthen her position 6.

• Yagami interprets her wager with Katsuragi as a deliberate attempt to make him gather school information while she preserves her reputation 6.
• Her proposed hawk-and-dove faction structure lets her supply aggressive ideas while Katsuragi bears responsibility for executing them 6.
• She recognizes the historical strategy Yagami calls “Dao King Qin Wang,” using the class’s collective interests to pressure Katsuragi into cooperation 26.

Information Gathering and Leverage

Information is one of Arisu’s principal weapons, used both to assess people and to threaten their reputations 8 21.

• She studies Hashimoto’s conversations and categorizes classmates by personality and potential usefulness 8.
• She recruits Kamuro to monitor Yagami and search for compromising behavior 17 18 19.
• She threatens Shiraishi Asuka with exposure of her supposed romantic scandals to stop her approaching Yagami 16 21.
• Limit: Asuka’s scandalous reputation is deliberately fabricated. Arisu fails to detect the disguise until Yagami explains it 21 25.

Academic Ability

Arisu’s excellent grades contribute to her standing in Class A. She also uses academic competition to try to establish authority over Yagami 4 29.

• She wagers that a victory over him will require him to consult her before acting 29.
• She wins their quiz contest by one point, but suspects that he deliberately engineered the result 31 32.
• She accepts Yagami’s midterm-question summary despite being confident in her own ability 41.
• Limit: She admits that precisely scoring one point below another person should be impossible for her; Yagami’s result leaves her confused and powerless 32.

Leadership and Point Management

Arisu warns classmates against treating their allowance as unconditional spending money and later becomes responsible for pooled funds 4 27 30.

• She urges students to save private points and repeatedly read the student handbook 4.
• Her authority supports Yagami’s rules for protecting class points through classroom discipline 11.
• She receives the class’s agreed point transfers after its first assessment success 30.
• She is willing to support Yagami’s plans financially, although she initially questions his motives 24 28.

Equipment / Items

• Cane — Supports her movement; she also raises it to strike Yagami during an argument, although her limited strength makes the gesture ineffective against him 3 31.
• Hat — Worn during her introduction and while following Yagami from the library 2 36.
• School-issued mobile phone — Used for private-point transactions and receiving funds entrusted to her 4 22 28.
• Borrowed surveillance equipment — Equipment from the Astronomy and Film Research Clubs, including a telescope with over one hundred times magnification and a camera, used to watch Yagami’s dormitory room 17 18 19.
• Kiryuin Fuka’s notebook — Given to her by Yagami as apparent evidence of obtained intelligence; its blank pages leave her questioning how he knows so much 10 11 12.

Relationships

• Yagami Shizuka — Confessor, strategic partner, and academic rival. She initially rejects his advances and seeks control over him, but increasingly trusts his judgment and appreciates his protection. A formally confirmed romantic relationship is not established in the supplied chapters 3 17 22 24 39.
• Chairman Sakayanagi — Her father. His position gives her social authority at school, and his explanations inform her understanding of the White Room 3 4 25.
• Katsuragi Kohei — Rival for Class A’s leadership and later a collaborator in its unification. She initially plans to exploit his faction rather than simply defeat it 6 24 26.
• Kamuro Masumi — Direct subordinate and reluctant surveillance partner. Arisu praises her ability to blend into crowds, while Kamuro objects to digging up dirt on Yagami 17 18 19 24.
• Hashimoto Masayoshi — Classmate whom she accepts as a friend and potential subordinate. His social connections help her assess the class 8.
• Shiraishi Asuka — Classmate and Seven Stars member. Arisu first intimidates her as a romantic intruder, then learns that her public reputation conceals a White Room background 16 21 24 25.
• Kiryuin Fuka — Yagami’s senior friend and a source of jealousy. Arisu nevertheless recognizes the strategic value of their friendship and later permits another outing 22 39.
• Horikita Manabu — Student council president. His dismissal of her contribution angers her; Yagami subsequently forces him to apologize publicly 32 37 38 39.
• Kushida Kikyo — Initially regarded as a highly useful Class D talent. After witnessing her hidden hostility, Arisu volunteers to handle Yagami’s proposed blackmail 36.

Story Role / Major Arcs

Arc	Chapters	Arisu’s involvement
First-day confession	2 3	Watches the emerging faction struggle, is startled by Yagami’s confession, and reveals her parentage to discourage further advances.
Contest for class leadership	4 6 8	Warns students about point spending, challenges Katsuragi, and begins assessing potential followers. Yagami explains how even losing her wager could benefit her.
Partnership under her authority	10 11 12	Reassesses Yagami after he obtains Kiryuin’s notebook. He credits her with his school intelligence and implements policies she approves.
Surveillance backfire	17 18 19 20	Uses Kamuro and borrowed equipment to seek leverage over Yagami. The plan stalls when they see him creating revealing face-swapped images of Arisu, making exposure potentially damaging to her as well.
Growing trust and class unification	21 22 24 25 27 28 29	Shares a cafeteria meal with Yagami, accepts points for safekeeping, supports fundraising, and joins the Seven Stars group. She acknowledges his success in uniting Class A rather than accepting undeserved credit.
Assessment success and academic rivalry	29 30 31 32	Class A finishes its first assessment with 990 class points. Arisu receives pooled funds but finds her one-point quiz victory over Yagami deeply unsatisfying.
Joint scheme against Kushida	36	Accompanies Yagami to the rooftop, witnesses Kushida’s hidden behavior, and volunteers to demand 40,000 points using the recording as leverage.
Public apology from the student council	37 38 39	Receives Manabu’s coerced apology and thanks Yagami for defending her, visibly moved by his support.
Midterm preparations	41	Accepts Yagami’s summary of likely exam questions to help secure first place; they plan to spend time together afterward.

Notable Quotes

“I do not allow anyone to exist beyond my control.” 17

“When facing an opponent, if you can win with a simple feint, why bother with a fair and square duel?” 19

“I think you are more suited to be the class leader than I am.” 28

“You are the ace of our class; it's best if you don't show your face to other classes.” 36