Orange

In the spring of her second year of high school, Naho receives a letter from her future self, predicting events with uncanny accuracy, including the arrival of a new student from Tokyo, Kakeru Naruse, who will sit next to her. The letter also urgently warns her not to invite Kakeru to join her friends on a specific day, raising questions about the reason behind the caution.

Kakeru joins the soccer club on a provisional basis, following the instructions in a mysterious letter. During a conversation about lunches after practice, he playfully asks Naho to make one for him. Naho is confused by his request but feels compelled to act, influenced by a letter from her future self urging her to do so.

Naho discovers a discrepancy between a letter predicting Kakeru's refusal to join the soccer club and his actual decision to do so, sparking hope that the future might still be changeable. However, her optimism is quickly tempered when she reads a new letter revealing that Kakeru and Ueda-senpai will begin dating.

Naho is distracted and emotionally troubled as Kakeru goes on a date with Ueda-senpai during the holidays, struggling to engage with her friends. Since Kakeru began dating Ueda-senpai, Naho has had difficulty communicating with him, and she regrets not expressing her true feelings to him when Ueda-senpai first asked him out. She now faces the challenge of dealing with her unresolved emotions.

Kakeru gives Naho a hairpin, and later invites her to study together for upcoming exams over the weekend. As their relationship develops, Naho musters the courage to ask Kakeru to join her for the fireworks at the end of the school festival.

On the final day of the school festival, Naho and Kakeru plan to watch the fireworks together, but Ueda-sama's sudden appearance creates a barrier between them. As the event begins, Naho faces uncertainty about whether she will be able to share the moment with Kakeru as she did in a previous timeline.

Naho and her friends from high school try to figure out what Kakeru wants for his birthday, while adult Naho and the group keep their promise to celebrate his birthday at his grandmother's house.

Naho has been following the advice from a letter she received from her future self, but begins to question its reliability. When the letter instructs her to prevent Kakeru from participating in the relay race at the athletic festival, she must decide whether to obey or act on her own judgment.

Naho feels reassured with the support of her friends and grows closer to Kakeru as the athletic festival approaches. As the big day arrives, Naho and her friends work together to ensure Kakeru can fully enjoy the event.

During the school athletic festival, Kakeru injures his ankle in the pole-toppling game but tries to hide it from his classmates. When Suwa and the others approach him, their concern helps him open up about his struggles. The episode culminates in the class relay race.

Naho, haunted by a New Year's Eve fight with Kakeru and unable to apologize before his death, as foretold in a letter from the future, confronts the same night with renewed determination to face whatever challenges lie ahead.

Kakeru moves to Matsumoto with his mother, who has her own reasons for the relocation. After she unexpectedly passes away on the first day of school, Kakeru struggles with guilt and withdraws from social interactions, including a soccer club invitation from Suwa. Feeling isolated and unable to connect with his former classmates, Kakeru spirals into deep emotional distress.

Naho struggles to give Kakeru her Valentine's Day chocolate as he continues to distance himself following the events of New Year's Eve. Determined not to give up, she remains resolved to express her feelings to him. As tensions rise, the group approaches the significant day foretold in the mysterious letters—known as "Kakeru's Final Day.