Karuizawa Kei

Biodata

Feature	Information
Name	Karuizawa Kei (轻井泽惠)
Gender	Female
Affiliation	Advanced Nurturing High School; Class D
Occupation/Role	Student
First Appearance	Chapter 4

Power Progression

Stage / Realm / Level	Chapter	Notes
Basic grappling training	45	Xia Mu begins teaching her foundational self-defense and grappling techniques during the deserted-island exam.
Correction progress: 20%	47	Her growing ability to defend herself without Hirata’s protection earns Xia Mu ten Skill Points through the Correction system.

Background / History

Karuizawa maintains a tough, domineering public persona, but this front conceals severe fear and vulnerability caused by past school bullying. She bears a scar on her abdomen from that period; after reporting the abuse, the perpetrators faced only brief consequences and later bullied her more severely. The experience left her terrified of appearing weak or returning to the life she escaped. 42 43

Before the cruise-ship trip, she spends her points cultivating relationships with Class D’s girls and borrows 10,000 points from Xia Mu when she runs out. She calls Hirata her boyfriend, though Xia Mu recognizes that their relationship is not what it appears to be. 17

On the cruise ship, her attempt to preserve her strong image leads her to harshly dismiss a girl she accidentally collides with. Once alone, she breaks down in fear. Xia Mu confronts her with knowledge of her past bullying and initiates a Correction mission focused on helping her overcome her dependence and fear. 42 43

During the deserted-island assessment, Xia Mu secretly contacts Kei and trains her nightly in grappling. Though initially resentful and suspicious of his motives, she gradually accepts the instruction and gains the ability to protect herself without relying on Hirata. 44 45 47

Appearance

Kei is described as wearing her hair in a high ponytail. She projects a confident, forceful image in public, though her posture and expression change sharply when she is alone or confronted with reminders of her past. 17 42

• Has a scar on her abdomen left by past bullying. 43
• Wears a tough expression and speaks sharply to sustain her public persona. 42
• Trembles, coughs, and retches when overwhelmed by memories of her abuse. 42

Personality

Kei is deeply afraid of being victimized again. Her aggressive behavior is primarily defensive: she believes that showing weakness would expose her to the same treatment she suffered in the past. This fear drives her to maintain a dominant facade even when it conflicts with her instinct to apologize or help others. 42

Despite this insecurity, she acts decisively when she sees others being bullied. She intervenes when Sudo, Yamauchi, and Kanji corner Xia Mu, using a recording threat to force them away even though Sudo’s raised fist causes her legs to weaken. 4

Her attitude toward Xia Mu changes through his self-defense training. She begins with fear and resentment, but comes to appreciate that he is teaching her to fight back rather than merely offering protection she would become dependent on. 43 45 47

Abilities & Skills

Social Defense and Intimidation

Kei uses confidence, status, and threats of official consequences to protect herself and others.

• Threatens to submit a recording to Chabashira when Sudo’s group threatens Xia Mu. 4
• Maintains an intimidating persona in public to avoid being perceived as vulnerable. 42
• Her reliance on this facade is unstable; isolation or reminders of past bullying can cause her composure to collapse. 42

Basic Grappling

Xia Mu trains Kei in foundational grappling during the deserted-island exam. 45

• Learns techniques intended to handle ordinary students who rely on numbers rather than formal combat training. 45
• Is described as physically supple, quick to understand instruction, and able to grasp moves rapidly. 47
• By the end of the training period, she possesses some ability to defend herself even without Hirata’s protection. 47

Relationships

• Xia Mu — Initially saved him from Sudo’s group; later borrows points from him. He exposes her past, begins her Correction, and trains her in self-defense. Her resentment gradually turns to gratitude. 4 17 42 45 47
• Hirata — Publicly identified by Kei as her boyfriend; she previously relies on his protection and social position. 17 43 47
• Sudo Ken, Yamauchi Haruki, and Kanji Ike — Kei intervenes when they threaten Xia Mu, driving them off with the threat of recorded evidence. 4
• Class D girls — Kei spends heavily to maintain good relationships with them, exhausting her available points. 17
• Ayanokoji Kiyotaka — Observes Xia Mu’s nighttime self-defense training with Kei on the deserted island. 45

Story Role / Major Arcs

Intervention Against Sudo’s Group

Kei prevents Sudo, Yamauchi, and Kanji from escalating their intimidation of Xia Mu. Although frightened, she refuses to retreat and uses her phone as leverage. 4

Financial Trouble

After spending her points on relationships within Class D, Kei privately asks Xia Mu for a loan and receives 10,000 points. 17

Cruise Ship Confrontation

Xia Mu witnesses the gap between Kei’s domineering public behavior and her private terror. He confronts her with knowledge of her bullying history, photographs her scar, and identifies her dependence on others for protection as a central issue. 42 43

Deserted-Island Self-Defense Training

Kei receives secret messages from Xia Mu and meets him at night for grappling instruction. Her training reduces her hostility toward him, improves her confidence, and advances her Correction progress to 20%. 44 45 47

Trivia

• Kei notices the indentation of Xia Mu’s footprint after saving him from Sudo’s group, leading her to wonder how anyone could possess such strength. 4
• During the island exam’s investigation into stolen underwear, she publicly vouches that Xia Mu is not responsible. 49