Mizuki Kitahara

Quick Facts

• Role: Class president; narrator of “The Martyr”
• First appearance: Second chapter (“The Martyr”), where she addresses her account directly to Yūko
• Key relationships: Shūya Watanabe; Naoki Shitamura; Yūko Moriguchi; Werther (Yoshiteru Terada)

Who They Are

Mizuki Kitahara is the class’s steady surface—orderly, smart, and attuned to the room’s “aura”—who slowly becomes the story’s most tragic collateral damage. Her chapter-length testimony turns her from passive observer into implicated participant as she documents how a single confession poisons a classroom’s social ecosystem. Defined less by appearance than by internal voice and by how others name her—Ayako’s revival of the despised nickname “Mizuho”—Mizuki’s identity oscillates between how she sees patterns and how she is seen. Her defining flaw is that she trusts her perceptions more than the people who confound them: she believes she can read Shūya, puncture lies, and intervene meaningfully, only to be undone by the rift between what she observes and what actually is—a textbook case of Perception vs. Reality.

Personality & Traits

Mizuki’s narration showcases a mind that watches, measures, and then acts—carefully, even scientifically. Yet the same sensitivity that lets her notice social shifts leaves her exposed to loneliness. When the class turns on Shūya, she splits herself in two: the rational witness and the frightened survivalist.

• Observant and atmospheric: She frames the class mood as an “aura,” identifying how collective emotions dictate behavior. Her sensitivity makes her a reliable barometer—and a vulnerable participant.
• Skeptical and empirical: The only student to question Yūko’s HIV-milk claim, she applies chemistry to test the cartons, proving a cool, methodical mind that refuses rumor.
• Pragmatic under duress: Knowing the cost of dissent, she joins the bullying to avoid becoming prey, revealing how fear metabolizes into complicity.
• Lonely and connection-seeking: Convinced she and Shūya are “alike,” she reaches for intimacy to escape isolation—precisely the need that Shūya exploits.
• Empathetic yet naïve: She feels for both Shūya and Naoki and reimagines Shūya as a misunderstood “saint,” a comforting fiction that blinds her to danger.

Character Journey

Mizuki begins as the dutiful class president trying to stabilize a shaken room after Yūko’s bombshell. When the class targets Shūya, she is coerced into participating, experiencing a jolt of “ecstasy” that horrifies and fascinates her—a glimpse of how collective cruelty seduces individuals. Her discovery that the milk was never contaminated isolates her from her peers and binds her to Shūya in a secret pact; she recasts herself as his protector and sole confidante, mistaking his coldness for wounded depth and her suspicion for intimacy. That misreading culminates in her attempt to “diagnose” him—calling out his “mother complex”—a move that, to Shūya, converts ally into enemy. He strangles her, and her arc closes where it began: trying to impose meaning on chaos. Mizuki becomes a casualty of the widening cycle of Revenge, proof that even the sharpest witness can’t out-think the harm that vengeance sets in motion.

Key Relationships

• Shūya Watanabe: Mizuki moves from fearful bystander to reluctant abuser, then to secret partner anchored by her discovery of the milk lie. She mistakes intellectual brilliance for moral depth and confuses her need to be needed with genuine understanding, turning herself into the perfect target for his manipulation.

• Naoki Shitamura: A childhood kindness flowers into a quiet, long-standing crush that colors Mizuki’s judgments. When Werther’s “help” precipitates Naoki’s breakdown and the killing of his mother, Mizuki’s anger fuses empathy with blame, revealing how her loyalties sharpen her moral clarity—and her misjudgments.

• Yūko Moriguchi: Addressing her chapter as a letter to Yūko, Mizuki admires the teacher’s intelligence while challenging the ethics and accuracy of her revenge. She asks Yūko to reckon with unintended consequences, positioning herself as both student and conscience—even as she underestimates the forces Yūko set in motion.

• Werther (Yoshiteru Terada): Mizuki sees through his performative “buddy” persona, judging him as a narcissistic amateur out of his depth. Her contempt underscores how adult failures amplify student harm by misreading the room Mizuki reads so well.

Defining Moments

Mizuki’s turning points trace the path from cool interpreter to doomed participant—each choice narrowing her exits.

• Narrating “The Martyr”: In Chapter 2, Mizuki’s voice maps the class’s moral freefall, establishing her as the story’s most precise social cartographer—and foreshadowing how observation won’t save her.
• Testing the milk cartons: By proving the HIV claim false, she separates fact from rumor and herself from the herd. The discovery forges a clandestine tie with Shūya—knowledge becomes intimacy, and intimacy becomes peril.
• The forced kiss: Coerced into throwing milk and then kissing Shūya for a humiliating photo, she experiences both complicity and victimization. The shared trauma welds her to him, collapsing her skepticism into a distorted loyalty.
• The confrontation and murder: Naming his “mother complex,” she tries to convert insight into cure; to Shūya, it is betrayal and exposure. His swift strangling of her reveals the lethal gap between psychological diagnosis and actual power.

Essential Quotes

It’s this: Can you feel it in the air? Do you sense it in the atmosphere? Whether it’s stale or fresh, stagnant or fluid? I’m convinced that the auras of all the people in any place get together to create the mood.

Mizuki translates social life into weather, making the classroom a pressure system that shapes individual behavior. The metaphor signals her strength—reading the room—and her weakness: believing awareness alone confers safety.

I got up and took a few steps toward him. Then I aimed at his chest, shut my eyes, and threw the carton as hard as I could. I could hear it bursting, and at that instant, I felt this weird kind of ecstasy come up from somewhere deep inside me.

The “ecstasy” captures how violence can intoxicate even the conscientious when crowd logic takes over. Mizuki’s horror at her own exhilaration marks the moment she recognizes complicity as a feeling, not just a fact.

At that moment I felt like Shūya was the only one in the world on my side.

Loneliness reframes Shūya as savior, not threat. This self-soothing belief becomes the gateway to manipulation, illustrating how desire for belonging can overwrite evidence.

Moriguchi-sensei, do you mind if I ask you one last question? What do you think of your revenge now?

Mizuki’s final appeal challenges Yūko to assess outcome rather than intention, pressing the moral costs onto the person who initiated them. It is a plea for accountability inside a spiral that has already outgrown anyone’s control.