The narrator finds an anonymous note inside his pencil case at school that says 'We should be friends.'

The narrator goes to the park to meet the anonymous note writer and discovers it is his classmate Kojima.

Ninomiya gags and binds the narrator and locks him inside a classroom locker while his friends look on.

Kojima and the narrator meet secretly in the school stairwell; she confesses she has been cutting curtains and objects to cope.

Kojima invites the narrator to visit a special place she calls 'Heaven' once their summer vacation begins.

Kojima takes the narrator to an art museum and shows him the painting she has renamed 'Heaven.'

Ninomiya and the other bullies drag the narrator to the school gym and take turns kicking him like a soccer ball.

After the bullies leave the gym, Kojima enters to help the narrator and urges him to start fighting back.

The narrator confronts Momose outside the hospital and demands that Momose and the others stop bullying him.

Momose tells the narrator that the bullying has nothing to do with his lazy eye — he is simply a convenient outlet.

A doctor tells the narrator that his lazy eye can be corrected with a simple and inexpensive surgery.

The narrator tells Kojima about the surgery option; she is devastated and accuses him of wanting to abandon the weak.

Ninomiya and the bullies ambush the narrator at the park, revealing they forced Kojima to write the letter summoning him.

Ninomiya throws Kojima to the ground after she touches his face, and she becomes unresponsive.

The narrator undergoes successful corrective eye surgery and weeps at the beauty of the world when he removes his bandage.

A bullied middle school boy begins receiving anonymous notes from a classmate named Kojima, who also suffers at the hands of their tormentors. They form a secret friendship and Kojima takes the narrator to an art museum to show him her vision of a harmonious world she calls 'Heaven.' After a severe beating by Ninomiya and his gang, the narrator confronts one of the bullies at a hospital and learns a disturbing philosophy about human cruelty. A doctor offers the narrator the chance to fix his lazy eye, but when he tells Kojima, she is devastated and accuses him of abandoning the weak. The bullies discover the friendship and spring a trap, leading to a violent climax at the park where Kojima is badly hurt standing up to them. The narrator ultimately has corrective eye surgery and weeps at the beauty of the world he sees with new clarity.

The headline events of the narrator's bullying, friendship with Kojima, and final transformation.

Ninomiya and his friends force the narrator to eat all three pieces of chalk during a classroom bullying episode.

The narrator writes his first letter to Kojima, filling it mainly with unimportant details about his daily life.

The narrator and Kojima ride the train to the art museum; she explains her invented word 'happamine.'

Kojima has a panic attack outside the museum and the narrator offers to let her cut off some of his hair.

The narrator watches a TV news report about a bullied student who died by suicide, which deepens his own fears.

The narrator walks to Kojima's house hoping to bump into her but abandons the plan after seeing her large gated home.

Kojima calls the narrator at home and asks him to meet her at the school stairwell before summer ends.

Kojima describes the night her mother threw a teacup at her father and walked out of the family's home.

Kojima sends the narrator an unusually long letter about her first argument with her stepfather, but he cannot bring himself to reply.

The narrator and his stepmother attend a family funeral and leave early; his stepmother buys salt to purify their home.

The narrator returns to school to find his desk stuffed with garbage, and Ninomiya threatens him with a game after school.

The narrator spots Momose at the hospital waiting room and quietly sits down beside him without speaking.

The narrator's stepmother accidentally cuts herself on a kitchen knife and is taken to the hospital by ambulance.

The narrator's stepmother mentions the possibility of divorcing the narrator's frequently absent father over dinner.

The narrator finally confesses to his stepmother that he has been bullied throughout his time at school.

Behind the main arc of bullying and friendship, a web of smaller events steadily shapes the narrator's character and relationships. The narrator and Kojima build their connection through letters and shared experiences, from a train ride to a museum to long summer letters about their families. Summer is marked by a disquieting TV news report and the narrator's failed attempt to visit Kojima's house, followed by a reunion that deepens their bond. Back at school, bullying escalates, and then a quiet moment at a hospital waiting room gives the narrator his first real look at one of his tormentors as a human being. Meanwhile, the narrator's home life quietly unravels as his stepmother faces her own crisis with a kitchen injury and the possibility of divorce. All these details converge as the narrator finally opens up to his stepmother about the years of bullying he has endured.

The smaller but vital moments shaping the narrator's world and inner life.

Despite suspecting a trick, the narrator decides to go to the park to meet the anonymous note writer.

The narrator and Kojima agree to exchange secret letters but decide never to acknowledge each other openly at school.

After their first stairwell meeting, the narrator recalls how his stepmother arrived at his family home during his childhood.

On the last day before summer break, the narrator secretly watches Momose writing tenderly in a notebook beside a younger girl.

Kojima explains that the painting 'Heaven' depicts two lovers who live in perfect harmony despite the suffering in their lives.

Kojima cuts off a fistful of the narrator's hair at the museum but refuses to throw it away, unlike everything else she cuts.

Kojima reveals she stays messy to feel connected to her struggling father and admits she researched lazy eyes before befriending the narrator.

Kojima tells the narrator that his lazy eye is her favorite thing about him and they hold hands for the first time.

After being severely beaten by the bullies, the narrator develops insomnia and begins thinking about suicide as a way to vanish.

Momose tells the narrator that guilt is the only thing truly separating him from the people who bully him.

While the narrator ignores Kojima's letters, he notices she has grown visibly thinner and more defiant toward her bullies.

At the park, the narrator tries to take the blame for the secret correspondence and begs the bullies to release Kojima.

The narrator picks up a rock at the park, but Kojima grabs his arm and prevents him from using it.

As Kojima touches each bully's face, the narrator realizes that her philosophy and Momose's both lead to the same core value of self-determination.

The narrator tells his stepmother that his birth mother also had a lazy eye; his stepmother gently encourages him to have the surgery.

Beneath the surface of events, a series of quiet but consequential revelations shapes who the narrator becomes. From his initial decision to trust Kojima's letter rather than dismiss it as a trick, to the moment she tells him his lazy eye is her favorite thing about him, each turn deepens his self-understanding. Kojima's description of the painting 'Heaven' and her refusal to discard his cut hair signal just how seriously she takes their bond. After the brutal gym attack, the narrator's insomnia and dark thoughts push him toward a new reckoning, which intensifies when Momose insists that guilt alone separates the narrator from his bullies. At the park, the narrator's attempt to protect Kojima and his sudden insight about the two philosophies he has been weighing mark his true coming-of-age moment. The story closes with a final revelation about his birth mother's lazy eye, unlocking the surgery's deeper emotional meaning.

The key decisions, discoveries, and emotional shifts that drive the narrator's growth.