[5] In the game, the player must figure out what happened to the character of Aya, a girl who mysteriously vanished after receiving a particular letter.

[6] Root Letter is set in Matsue, Shimane Prefecture, where the protagonist arrives in search of Fumino Aya, a pen pal friend from high school who had disappeared for 15 years.

[5] After he finds a letter dedicated to him from her that was never sent, he sets out to interrogate her classmates as he wonders if everything Aya had told him had been a lie.

[16] A live-action video project based on the original game is additionally planned to be produced by Perfect World Pictures.

[25] Despite the game not appearing on the weekly Media Create charts again in Japan, worldwide sales passed 200,000 copies sold by January 2017, making it a commercial success.

[29] Geraint Evans, the head of marketing of PQube, called their Root Letter sales "phenomenal", with the vast majority sold on the PlayStation Vita.

[31][32] The film, produced and financed by Akatsuki Entertainment, is directed by Sonja O'Hara, written by David Ebeltoft, produced by Annmarie Sairrino, Moeko Suzuki, and Kat McPhee, and starring Danny Ramirez, Keana Marie, and Lydia Hearst, began shooting in Shreveport, Louisiana on September 16, 2019.

The film was released on September 1, 2022,[4] and is envisioned as a gritty re-imagining of the game's core story of a protagonist in search of a former pen pal who disappears under mysterious circumstances.