[2][3] The series follows high schoolgirl Naho Takamiya, who receives a letter written by herself ten years in the future.

She is tasked with keeping an eye on Kakeru Naruse, a transfer student whose mother committed suicide on his first day of school.

[7] A spin-off to the manga began serialization on March 25, 2016, in the Monthly Action magazine published by Futabasha.

In Matsumoto, Naho Takamiya, a second-year high school student, receives letters sent from herself 10 years into the future.

Her future self asks her to prevent her "biggest regrets", which has something to do with the new transfer student from Tokyo, a boy named Kakeru Naruse.

To prevent another mistake, Naho resolves to do what the letters order her to do, such as volunteering on a softball round, encouraging Kakeru to join the soccer team, objecting to him pursuing a relationship with an upperclassman, and insisting they watch the fireworks alone.

During the Bon Festival, Kakeru explains to Naho the reason for his absence: his mother died by suicide because of a mental breakdown caused by him leaving her for friends, and not taking her to the hospital on the day of enrollment as he promised.

Later on, Suwa tells Naho he has also received letters from his future self, asking him to be a good friend to Kakeru and save him from his death.

[8] A live-action film adaptation was released on December 12, 2015 in Japan with Tao Tsuchiya and Kento Yamazaki as the main characters; directed by Kojiro Hashimoto and written by Arisa Kaneko.

The anime adaptation of Orange is produced by Telecom Animation Film and directed by Hiroshi Hamasaki and Naomi Nakayama, with Yūko Kakihara handling series scripts, Nobuteru Yūki designing the characters and Hiroaki Tsutsumi composing the music.

[56] The English release was reviewed favorably by Rebecca Silverman of Anime News Network, who gave both omnibus collections an overall A− score.

She praised the "poignant and moving" story, but warned the issue of suicide may make it a difficult read for some people.

[57] Eva de Gans of Dutch magazine Aniway recommended the series, praising its visuals and "endearing and relatable" cast of characters, while criticizing Naho and Kakeru's characterizations as passive, timid characters and the "unconvincing" explanation of the time travel.