Arisa Sonoda, a seemingly popular and well-adjusted middle school student, hides her turmoil behind a facade of perfection, a stark contrast to her twin sister Tsubasa. Separated from Tsubasa after their parents' divorce, Arisa masked her struggles through meticulously crafted letters, concealing her role in a sinister classroom hierarchy revolving around the enigmatic King—a figure who granted classmates’ wishes through manipulative or violent means.

Initially conceived to unify her class through benign favors—such as aiding a peer’s academic struggles—the King’s demands grew darker under the weight of Arisa’s desperation for validation. She resorted to stealing exam answers, a transgression discovered by her boyfriend Midori. Forced into collaboration, Arisa watched helplessly as Midori twisted the role, orchestrating false accusations and physical assaults. His brutality reached its peak when he harmed Arisa’s mother, a betrayal that shattered her illusions. Haunted by their shared culpability, she staged a suicide to break free and spur Tsubasa’s pursuit of the truth.

After awakening from a coma, Arisa buried her memories to evade consequences, yet fractured recollections surfaced over time. Confessing her guilt, she disclosed unresolved affection for Midori, whose own trauma—rooted in childhood abandonment and the loss of his twin sister—warped his morality. Drawn to his isolation, Arisa continued visiting him in prison, seeking absolution through their fractured bond.

Arisa’s journey traces a shift from complicity to accountability, motivated by a determination to shield others from repeating her mistakes. Her complex relationship with Tsubasa mirrored struggles with identity and sisterhood, transforming jealousy into gratitude as Tsubasa unraveled the King’s legacy. Ultimately reconciling with her mother and confronting her history, Arisa’s story interrogates the corrosive weight of guilt, the burdens of responsibility, and the chains of societal expectation.