The first part of the final chapter of Koudon’s manga adaptation of Mokune Hachi and Kukka’s The Tunnel to Summer, the Exit of Goodbye (Natsu e no Tunnel, Sayonara no Deguchi) novel launched on Shogakukan‘s Manga ONE app on Saturday. The term used for the “first part” of the final chapter indicates only a two-part series, so the manga will end with the second part of the final chapter.
Seven Seas Entertainment has licensed both the manga and the original light novel, and it describes the story:
Tono Kaoru heard a rumor: The laws of space and time mean nothing to the Urashima Tunnel. If you find it, walk through and you’ll find your heart’s desire on the other side…in exchange for years of your own life. On the night Kaoru just so happens to find himself standing in front of a tunnel that looks suspiciously like the one the rumor describes, he finds himself thinking of Karen, the sister he lost in an accident five years ago. To Kaoru’s surprise, he’s been followed by the new transfer student Anzu Hanaki, who promises to help him experiment with the mysterious tunnel–but what does she want from Kaoru in exchange? And what will he have left to give, after the tunnel’s done with him?
Koudon launched the manga in Shogakukan‘s Sunday GX magazine in July 2020, and the manga serializes both on Manga ONE and in Sunday GX. Shogakukan published the manga’s third compiled book volume on August 19.
Hachi released the original light novel in July 2019, with illustrations by Kukka. The novel was ranked #9 in the bunkobon category of 2020 edition of Takarajimasha‘s Kono Light Novel ga Sugoi! (This Light Novel Is Amazing!) guidebook. Seven Seas will publish the novel and the first volume of the manga in July 2022.
Source: Manga ONE app’s Twitter account