Confessions recap

Before resigning, teacher Yuko Moriguchi tells her class that students Shuya Watanabe and Naoki Shimomura killed her four-year-old daughter Manami. She claims to have put blood from Manami's HIV-positive father into their milk, setting off terror and retaliation. Classmates persecute Shuya, while Naoki withdraws at home and eventually kills his mother. Successive narrators reveal that Shuya's electrical device only stunned Manami; Naoki, believing he had failed to prove himself, deliberately drowned her. Shuya, obsessed with the scientist mother who abandoned him, embraces notoriety, kills the classmate who understands him best, and plants a bomb at a school ceremony. Moriguchi ultimately reveals that the blood was never infected. She has discovered the bomb and moved it to the university office of Shuya's mother. When Shuya triggers it, the explosion occurs there instead of at the school, apparently killing the person he most wanted to impress. Moriguchi tells him that his real lesson has only begun.

On her final day as a middle-school teacher, Yuko Moriguchi tells her class that the recent drowning of her four-year-old daughter Manami was not an accident. She identifies two students, initially called A and B, as responsible. Student A, the inventive Shuya Watanabe, built an electrified purse and tested it on the child in pursuit of attention. Student B, Naoki Shimomura, assisted him. Because juvenile law will protect the boys, Moriguchi has devised a private punishment. Manami's father, educator Masayoshi Sakuramiya, carries HIV. Moriguchi says she mixed his blood into the milk cartons Shuya and Naoki have just emptied, leaving them to fear infection. She explains that the virus is not spread casually and presents the act as a lesson in the value of life. The class recognizes both boys despite her nominal anonymity, and Moriguchi leaves the school after setting the consequences in motion.

Mizuki Kitahara describes the class after Moriguchi's departure. Their new teacher, Yoshiteru Terada, brings energetic optimism and reverence for Sakuramiya's ideals, unaware of the full history. Classmates turn Moriguchi's accusation into an organized campaign against Shuya, using the fear of HIV to isolate and humiliate him while pretending their conduct is morally justified. Mizuki refuses to participate and communicates with Shuya, who converts persecution into another stage for his need to be noticed. Naoki stops attending school, and Terada repeatedly visits his home in the belief that persistence will restore him. The public performance of concern intensifies the pressure on both boys rather than producing remorse. Mizuki sees that the class's cruelty and Shuya's cultivated indifference feed each other, while Moriguchi remains absent from the institution where her accusation continues to shape everyone.

Naoki's mother recounts his collapse at home. She believes Shuya manipulated her fundamentally kind son and regards Moriguchi's blood threat as the true source of the family's suffering. Naoki shuts himself away, refuses school, neglects his body, and becomes obsessed with contamination. His mother shields him from scrutiny and resents Terada's repeated visits, though she outwardly receives the teacher's encouragement. Her devotion depends on separating the child she loves from responsibility for Manami's death. As Naoki's behavior grows more frightening, she begins to see that recovery may require acknowledgment and outside intervention. Her attempt to confront the reality of what he has done destroys the refuge she built around him: Naoki attacks and kills her. The violence reveals that protection based on denial has neither healed him nor kept the family safe.

Naoki's own account corrects a central assumption about Manami's death. Shuya's device stunned the child but did not kill her. When Naoki realized she was still alive, he felt that his assigned role had left him insignificant beside Shuya. He placed Manami in the swimming pool and drowned her, turning a failed demonstration into murder. After Moriguchi's announcement, fear of infection, shame, and resentment become rituals of isolation and compulsive cleaning. Terada's visits feel like invasions, and his mother's insistence on innocence prevents Naoki from speaking honestly about what he did. When she finally moves toward admitting his responsibility and ending their seclusion, he interprets it as abandonment and kills her. His confession makes clear that he was neither merely Shuya's passive tool nor the blameless victim his mother needed him to be.

Shuya explains that his inventions and crimes have always been directed toward his absent mother, a gifted scientist whose recognition he values above ordinary affection. He wanted the purse device to make him famous enough for her to notice, and Manami became a means to that end. He takes pride in manipulating Naoki and in controlling the class's response to Moriguchi's accusation. Mizuki comes closest to understanding the abandonment beneath his performance, but when her insight threatens the identity he has constructed, he kills her. Shuya then prepares a larger act: a bomb hidden at a school ceremony, intended to kill many people and attach his name permanently to the event. He records his history and motives online, expecting his mother and the public to encounter the account after the attack. At the ceremony he initiates the device, convinced that mass death will complete his transformation into someone impossible to ignore.

The school does not explode when Shuya activates his bomb. Moriguchi contacts him and reveals that she has followed his preparations. She also removes the premise that began the class's panic: the milk contained no HIV-infected blood. Her revenge worked through suggestion, social cruelty, and the boys' own choices rather than deliberate infection. Having found the bomb, she transferred it away from the students and into the university office of Shuya's mother. News of an explosion there turns his intended triumph into the apparent death of the person whose attention motivated his inventions and murders. Moriguchi tells him that this consequence is the beginning of his reckoning, not a restoration of what she lost when Manami died. Her last, cutting retraction leaves a sliver of uncertainty around the precise claim, but the plan's essential result is clear: the school is spared, Shuya is broken by the fate of his mother, and Moriguchi completes a revenge tailored to what each killer valued most.

Shuya completes his plan to turn a school ceremony into the spectacular crime he believes will finally make his mother notice him. After activating the bomb remotely, he hears no explosion at the school. Moriguchi calls and explains the remaining pieces of her revenge. The blood placed in the boys' milk was not infected; she relied on fear and on the consequences of their own characters rather than exposing children to HIV. She learned of Shuya's bomb, removed it from the school, and placed it in the university office of the mother he idolizes. An explosion reported there means that Shuya's attempt at recognition has apparently killed the person whose approval motivated it. Moriguchi presents this loss as the beginning of his moral reckoning, mirroring the loss of Manami without claiming that the two deaths can truly balance. Her final sardonic qualification introduces a last note of uncertainty, but Shuya's triumph has plainly been converted into devastation and Moriguchi has completed the revenge she designed around each boy's weakness.