Sakayanagi Arisu

Biodata

Feature	Details
Name	Sakayanagi Arisu (扳柳有栖)
Alias(es)	Eris
Species/Race	Human
Gender	Female
Affiliation	Tokyo Advanced Nurturing High School (ANHS); Class 1-A; Student Council; later Chairman of ANHS
Occupation/Role	Student, strategist, Student Council member and vice president, later ANHS Chairman
Status	Alive
First Appearance	Chapter 83 (earliest provided appearance)

Background / History

Arisu was born with congenital heart disease and spent much of her childhood in hospital care. Her mother chose the name “Arisu,” after Alice in Wonderland, before her birth; Arisu was too young to remember her mother’s death and instead learned about her through her father, Sakayanagi Narimori. Her illness left her isolated and unable to take part in ordinary childhood experiences. 239 248

In a life simulation, Arisu met Kitagawa Ryo in the hospital ward next to hers. Ryo introduced her to Gomoku, chess, Go, and Chinese chess, becoming both her first peer connection and an opponent who repeatedly defeated her at games. Their conversations challenged her assumptions about dreams, death, and human connection. 233 234

As Ryo’s condition deteriorated from ALS in that simulation, Arisu cared for him, decorated a room for him, and resolved to study medicine in hopes of curing him. After he fell into a coma, she continued visiting him and adopted Hotaru, renaming the cat “Ryo.” A year later, Arisu underwent successful heart surgery and heard her own heartbeat clearly for the first time. 237 240

Arisu later received memories and emotions from two radically different simulations while retaining the life she had already lived with heart disease. The resulting mismatch between her recovered body, accumulated memories, and competing life perspectives contributed to a prolonged period of emotional instability. 285 590

Appearance

Arisu is a petite, slender girl with silver-white hair and deep violet eyes. Before her heart disease was cured, she was visibly frail, required a cane to go out, and had extremely low physical ability. 305 574

• Silver-white hair, generally shorter than Horikita Suzune’s or Ichinose Honami’s. 305
• Deep purple eyes. 234 628
• Often presents herself with refined, doll-like or princess-like fashion. 391
• Previously relied on a cane; after her treatment, she could walk without one, though her leg muscles remained weak from long-term inactivity. 372
• Her petite frame and pink-toned outfits are repeatedly associated with a childlike, elegant appearance. 305 391

Personality

Arisu is intensely proud of her natural intelligence and initially believes that a person’s potential is determined at birth. Even as a child, she spoke with unusual composure and confidence, showing no fear when publicly discussing her academic ability. 260

Her confidence can become arrogance, competitiveness, and a need to prove herself against rivals—especially those connected to the White Room or Kitagawa Ryo. She is capable of recognizing her own failures, however, and eventually admits that her past arrogance has exhausted her. 562 581

Despite her polished manners and social grace, Arisu has a possessive, jealous side toward Ryo. Her memories of caring for the weaker Ryo in the simulations leave her afraid that he might disappear from her life; this insecurity manifests in territorial behavior and a desire for public acknowledgment of their relationship. 392 497

Arisu also possesses a gentler, nurturing temperament. She cares for Hotaru, shows concern for students harmed by ANHS’s Class A-centered system, and ultimately seeks to improve the school rather than merely benefit from its resources. 283 590 632

Abilities & Skills

Academic Ability

Arisu is a recognized genius with exceptional academic performance from childhood.

• Placed third in a public academic event at age seven, demonstrating knowledge beyond that of an ordinary middle-school student. 260
• Excelled in Speed Mental Arithmetic, though she was later defeated by Ryo in a mental-arithmetic competition. 269 275
• Considers her study methods unsuitable for general use because of her belief in innate talent. 260
• Regularly takes first place in academic tasks during the Uninhabited Island Special Exam. 372

Chess and Board Games

Arisu is a highly skilled chess player whose chess matches often become extensions of her personal rivalries.

• Was introduced to board games by Ryo during their hospital childhood, beginning as a complete novice at Gomoku. 233
• Later possessed chess mastery beyond ordinary high-school amateur level. 560
• Played Ryo in chess and lost, prompting her curiosity over why she had been defeated. 172
• Represented Class 1-A in the Selection Exam’s final chess event against Amasawa Ichika. 560 561

Strategy and Information Gathering

Arisu is an effective planner who combines analysis, social intelligence, and access to elite networks.

• Built an intelligence network with students including Matsushita Chiaki during the Uninhabited Island Special Exam. 372
• Was assigned to memorize the remaining areas of the uninhabited island in three dimensions for her group’s final operation. 372
• Served as Kitagawa Ryo’s covert-side commander during the Cultural Festival, identifying noteworthy prospective students while he handled public-facing activities. 451
• Uses her social standing and understanding of student sentiment to build support during elections and class conflicts. 487 490

Social and Political Acumen

Arisu is highly polished in formal settings and understands the leverage attached to family background, institutional roles, and public opinion.

• Interacts smoothly with influential adults, including Kanzaki Ryuji’s father, and presents Ryo as a distant cousin when necessary. 258
• Joined the Student Council as a first-year member, though she initially treated the position as nominal. 207
• Lost the Student Council presidential election to Horikita Suzune, then chose to follow Nagumo Miyabi’s path by becoming Suzune’s vice president. 550
• Later became Chairman of ANHS after Sakayanagi Narimori transferred authority to her. 631

Equipment / Items

• Cane — Used to support her mobility before her heart condition was cured. 174 574
• Matching ring — Wears a ring on the middle finger of her left hand and gives Ryo a matching men’s ring during their date. 591
• Board-game sets — Chess, Go, and Chinese chess sets kept in her childhood hospital room. 233

Relationships

• Kitagawa Ryo — Childhood hospital companion in simulations, intellectual rival, and central romantic attachment. Arisu cared for him through terminal illness, later learns that he cured her heart disease in reality, and seeks to move forward with him openly. 237 285 591
• Sakayanagi Narimori — Her father and former ANHS Chairman. He deeply loves Arisu, supports her medical recovery and decisions, and eventually transfers the chairmanship of ANHS to her. 233 252 631
• Hotaru — A cat closely tied to Arisu’s memories of Ryo. In one simulation, Arisu adopts Hotaru and renames her “Ryo”; later, she learns to care for Hotaru more gently. 240 590
• Amasawa Ichika — White Room-linked rival. Their unresolved history turns a Selection Exam chess match into a personal confrontation, and they later cooperate at times despite continued hostility. 561 562 581
• Yuki / Tsubaki Sakurako — A rival connected to Ryo and the White Room. Their interactions are marked by provocation, jealousy, and mutual aggression. 452 574
• Horikita Suzune — Student Council colleague and political rival. Arisu competes with Suzune in the Student Council election, then serves as her vice president after losing. 476 550
• Ichinose Honami — A fellow student with comparable life-simulation experience. The two eventually cooperate to investigate their shared past with Ryo and participate in his festival. 628
• Ayanokoji Kiyotaka — A White Room-linked figure whose beliefs about talent clash with Arisu’s own. 236
• Ayanokoji Atsuomi — Founder of the White Room and an enemy in Arisu’s eyes because of his connection to Ryo’s suffering. 276 574

Story Role / Major Arcs

Hospital and Simulation Childhood

Arisu’s early simulated life centers on her isolation from illness and her growing bond with Ryo, who introduces her to games, challenges her self-image, and becomes the first person with whom she shares ordinary childhood experiences. 233 235

Ryo’s Illness and Arisu’s Recovery

As Ryo declines from ALS, Arisu becomes his caretaker and decides to pursue medicine. Following his coma, she endures grief and loneliness before undergoing successful surgery for her own heart disease. 237 240

White Room Investigation

After learning of the White Room, Arisu investigates its ideology and participants. Her experiences with Ryo make her hostile toward Ayanokoji Atsuomi, the project, and its supporters. 252 276 574

ANHS Student Council and Special Exams

At ANHS, Arisu initially joins the Student Council without actively participating. She later becomes a key strategist in the Uninhabited Island Special Exam and represents Class 1-A in chess during the Selection Exam against Ichika; Class 1-A ultimately loses the exam 4–3. 207 372 560 562

Election Rivalry and Vice Presidency

Arisu campaigns against Horikita Suzune for the Student Council presidency, using her social experience and political instincts to build support. Horikita wins, and Arisu accepts a vice-presidential role while continuing to pursue influence over ANHS’s future. 490 550

Reconciliation with Ryo

After withdrawing from Ryo because of fear and emotional confusion, Arisu admits that she had been running away from her problems. She begins dating him more openly, speaks with her father about their future, and gives Ryo a matching ring. 590 591

Chairmanship of ANHS

In a later period, Arisu succeeds her father as Chairman of ANHS. She aims to make ANHS the country’s leading high school through students’ actual ability rather than its resources alone. 631 632

Notable Quotes

“You can never dream about the people you want to see.” 234

“The moment a person is born, the moment they receive life, their potential is already determined.” 260

“Ryo’s task today is to go on a date with me.” 591

Trivia

• Arisu’s name is pronounced similarly to “Alice,” and her mother selected it in reference to Alice in Wonderland. 181 239
• She and Ryo once painted a vivid red rose on a hospital wall, making the flower a symbol of their bond. 236
• Her childhood belief in innate genius directly conflicts with the White Room’s project of creating “artificial geniuses.” 248 260