# The Summer Hikaru Died

The Summer Hikaru Died (Japanese: 光が死んだ夏, Hepburn: Hikaru ga Shinda Natsu) is a Japanese manga series written and illustrated by Mokumokuren. It began serialization on Kadokawa Shoten's Young Ace Up website in August 2021. As of December 2024, the series' individual chapters have been collected in six tankōbon volumes. It follows the story of Yoshiki, a teenager in rural Japan who discovers that his best friend Hikaru has been possessed by an otherworldly entity, forcing him to navigate their changed relationship amid supernatural dangers.
Mokumokuren first conceived of the series while studying for exams and later began posting drawings on Twitter, which led to the Young Ace Up editorial department approaching Mokumokuren to serialize the manga via the Young Ace Up website. An anime television series adaptation produced by CygamesPictures is set to premiere in Q3 2025.
Upon release of the first volume, the series became a critical and commercial success, with the first volume selling 200,000 copies in three months, and received critical praise for story, artwork, and characters.

## Plot

Yoshiki and Hikaru are two teenage boys living in a small town in rural Japan. Despite having opposite personalities and different hobbies, the two maintain a close friendship. However, on one winter day, Hikaru is fatally injured while hiking in the mountains alone. Before dying, a mysterious eldritch being comes across him and consumes him, becoming him physically in the process. This "Hikaru" has all the feelings and memories of the original, yet remains a separate being, something Yoshiki realizes rather quickly. Yoshiki still wants to stay with "Hikaru"; however, his alien nature, along with other eldritch beings and hunters of said beings, may make that impossible.

## Characters
### Hikaru Indo (忌堂 光, Indō Hikaru)

    Voiced by: Yōtarō Negishi (vomic, PV1), Hiro Shimono (PV2), KENN (PV3), Junya Enoki (PV4), Shūichirō Umeda (anime)

### Yoshiki Tsujinaka (辻中 佳紀, Tsujinaka Yoshiki)

    Voiced by: Tomohiro Ohno (vomic, PV1), Yoshitsugu Matsuoka (PV2), Tomoaki Maeno (PV3), Koki Uchiyama (PV4), Chiaki Kobayashi (anime)

## Production

Mokumokuren first conceived the series while studying for high school entrance exams. After graduating, Mokumokuren began posting drawings on Twitter in their spare time in January 2021. Mokumokuren was later approached by the Young Ace Up editorial department to serialize the manga in Young Ace Up, which they accepted. Mokumokuren is a fan of action manga from Weekly Shōnen Jump and Weekly Young Jump, particularly Tokyo Ghoul.
While writing the story, Mokumokuren tries to keep the horror to a minimum by trying to appeal to people's emotions rather than just being scary. Mokumokuren also feels the theme of the story adds to the horror based on the suspension bridge effect, which states that it is easier to fall in love when feeling anxious or fearful. For the artwork, Mokumokuren tries to use onomatopoeia that are not often used, while also staying cautious to make sure it works properly in the context of the story.
Mokumokuren introduced this as a one-shot in 2021 under the Boys' Love genre, but chose not to specify the genre of the official publication in 2022.

### Setting

Mokumokuren used their grandmother's hometown as model, where the houses were all packed together tightly and normal for the neighbors to come and go without permission. They got the inspiration during their visit to the region. As Mokumokuren wanted the characters to speak in distinctive dialect, they looked up for a dialect that is "slightly different from Kansai dialect" and decided the setting on place that is located in "mountainous area of Tokai region." As the result, a fictional rural town located between mountains in Mie Prefecture became the setting of the series, and some characters are speaking in Mie dialect.

## Media
### Manga

Written and illustrated by Mokumokuren, the series began serialization on Kadokawa Shoten's Young Ace Up website on August 31, 2021. As of December 2024, the series' individual chapters have been collected in six tankōbon volumes.
In September 2022, Yen Press announced that they licensed the series for English publication.

#### Volumes

| No. | Original release date | Original ISBN | English release date | English ISBN |
| 1 | March 4, 2022 | 978-4-04-112273-0 | July 18, 2023 | 978-1-97-536054-2 |
| 2 | October 4, 2022 | 978-4-04-112960-9 | October 17, 2023 | 978-1-97-537103-6 |
| 3 | June 2, 2023 | 978-4-04-113700-0 | April 16, 2024 | 978-1-97-539276-5 |
| 4 | December 4, 2023 | 978-4-04-114339-1 | August 20, 2024 | 978-1-97-539862-0 |
| 5 | June 4, 2024 | 978-4-04-114997-3 | March 25, 2025 | 979-8-85-541459-2 |
| 6 | December 4, 2024 | 978-4-04-115608-7 | — | — |

### Novel

A novelization of the manga series, written by Mio Nukaga, was published by Kadokawa Shoten on December 4, 2023. At New York Comic Con 2024, Yen Press announced that they also licensed the novel for English publication.

### Anime

An anime adaptation was announced on May 24, 2024. It was later revealed to be a television series produced by CygamesPictures and directed and written by Ryōhei Takeshita, with character designs and chief animation direction handled by Yuichi Takahashi, and "Dorodoro" animation handled by Masanobu Hiraoka. It is set to premiere in Q3 2025 on Nippon TV. Netflix will stream the series globally, with Abema streaming it inside Japan for free.

## Reception

In the 2022 Next Manga Award, The Summer Hikaru Died ranked 11th in the web manga category. It was also the most popular choice among traditional Chinese voters. The series topped the 2023 edition of Takarajimasha's Kono Manga ga Sugoi! list of best manga for male readers. It was also nominated for the 16th Manga Taishō. The series ranked fifth in the Nationwide Bookstore Employees' Recommended Comics of 2023. It also ranked seventh in the seventh Tsutaya Comic Award. In 2023, the series was listed by the New York Public Library among its Best Books for Teens that year. It ranked 29th on the 2023 "Book of the Year" list by Da Vinci magazine. In 2024, the first volume and series author Mokumokuren were nominated for the Eisner Award for Best U.S. Edition of International Material—Asia and for Best Writer/Artist respectively. The series was also nominated for Harvey Awards in the Best Manga category in the same year.
The first volume received three times more orders than copies available in the first print run. The volume was reprinted six times in three months, having over 200,000 copies in circulation. By October 2022, the series had 550,000 copies in circulation. By June 2023, the series had 1.4 million copies in circulation. By December 2023, the series had 1.9 million copies in circulation. By May 24, 2024, the series had 2.1 million copies in circulation. By June 4, 2024, the series had 2.3 million copies in circulation. By November 4, 2024, the series had 3 million copies in circulation.
Chanmei from Real Sound praised the story and characters as emotional. Chanmei also praised the artwork, believing it complemented the story well. Tensako Miura from An An praised the story, main characters, and artwork, positively noting the artwork's use of shades of black.